Microsoft Windows Server 2016 STIG
Microsoft Windows Server 2016 Security Technical Implementation Guide. Version v2 r8, released May 15, 2024.
WN16-CC-000410: Remote Desktop Services must be configured with the client connection encryption set to High Level.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services\ Value Name: MinEncryptionLevel Type: REG_DWORD Value: 0x00000003 (3)
Discussion
Remote connections must be encrypted to prevent interception of data or sensitive information. Selecting "High Level" will ensure encryption of Remote Desktop Services sessions in both directions.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Remote Desktop Services >> Remote Desktop Session Host >> Security >> "Set client connection encryption level" to "Enabled" with "High Level" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000430: Windows Server 2016 must be configured to use FIPS-compliant algorithms for encryption, hashing, and signing.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\Lsa\FIPSAlgorithmPolicy\ Value Name: Enabled Value Type: REG_DWORD Value: 0x00000001 (1) Clients with this setting enabled will not be able to communicate via digitally encrypted or signed protocols with servers that do not support these algorithms. Both the browser and web server must be configured to use TLS; otherwise. the browser will not be able to connect to a secure site.
Discussion
This setting ensures the system uses algorithms that are FIPS-compliant for encryption, hashing, and signing. FIPS-compliant algorithms meet specific standards established by the U.S. Government and must be the algorithms used for all OS encryption functions. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000478-GPOS-00223
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "System cryptography: Use FIPS compliant algorithms for encryption, hashing, and signing" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000200: The setting Microsoft network client: Digitally sign communications (if server agrees) must be configured to Enabled.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters\ Value Name: EnableSecuritySignature Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
The server message block (SMB) protocol provides the basis for many network operations. If this policy is enabled, the SMB client will request packet signing when communicating with an SMB server that is enabled or required to perform SMB packet signing. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Microsoft network client: Digitally sign communications (if server agrees)" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000040: Administrative accounts must not be used with applications that access the Internet, such as web browsers, or with potential Internet sources, such as email.
Determine whether organization policy, at a minimum, prohibits administrative accounts from using applications that access the Internet, such as web browsers, or with potential Internet sources, such as email, except as necessary for local service administration. If it does not, this is a finding. The organization may use technical means such as whitelisting to prevent the use of browsers and mail applications to enforce this requirement.
Discussion
Using applications that access the Internet or have potential Internet sources using administrative privileges exposes a system to compromise. If a flaw in an application is exploited while running as a privileged user, the entire system could be compromised. Web browsers and email are common attack vectors for introducing malicious code and must not be run with an administrative account. Since administrative accounts may generally change or work around technical restrictions for running a web browser or other applications, it is essential that policy require administrative accounts to not access the Internet or use applications such as email. The policy should define specific exceptions for local service administration. These exceptions may include HTTP(S)-based tools that are used for the administration of the local system, services, or attached devices. Whitelisting can be used to enforce the policy to ensure compliance.
Fix
Establish a policy, at minimum, to prohibit administrative accounts from using applications that access the Internet, such as web browsers, or with potential Internet sources, such as email. Ensure the policy is enforced. The organization may use technical means such as whitelisting to prevent the use of browsers and mail applications to enforce this requirement.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-CC-000040: Internet Protocol version 6 (IPv6) source routing must be configured to the highest protection level to prevent IP source routing.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters\ Value Name: DisableIPSourceRouting Type: REG_DWORD Value: 0x00000002 (2)
Discussion
Configuring the system to disable IPv6 source routing protects against spoofing.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> MSS (Legacy) >> "MSS: (DisableIPSourceRouting IPv6) IP source routing protection level (protects against packet spoofing)" to "Enabled" with "Highest protection, source routing is completely disabled" selected. This policy setting requires the installation of the MSS-Legacy custom templates included with the STIG package. "MSS-Legacy.admx" and "MSS-Legacy.adml" must be copied to the \Windows\PolicyDefinitions and \Windows\PolicyDefinitions\en-US directories respectively.
Rating Info
DISA Cat III. NIST impact 2.
Expert Comment
None
WN16-SO-000040: Windows Server 2016 built-in guest account must be renamed.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options. If the value for "Accounts: Rename guest account" is not set to a value other than "Guest", this is a finding. For server core installations, run the following command: Secedit /Export /Areas SecurityPolicy /CFG C:\Path\FileName.Txt If "NewGuestName" is not something other than "Guest" in the file, this is a finding.
Discussion
The built-in guest account is a well-known user account on all Windows systems and, as initially installed, does not require a password. This can allow access to system resources by unauthorized users. Renaming this account to an unidentified name improves the protection of this account and the system.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Accounts: Rename guest account" to a name other than "Guest".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AC-000070: Windows Server 2016 minimum password length must be configured to 14 characters.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Password Policy. If the value for the "Minimum password length," is less than "14" characters, this is a finding. For server core installations, run the following command: Secedit /Export /Areas SecurityPolicy /CFG C:\Path\FileName.Txt If "MinimumPasswordLength" is less than "14" in the file, this is a finding.
Discussion
Information systems not protected with strong password schemes (including passwords of minimum length) provide the opportunity for anyone to crack the password, thus gaining access to the system and compromising the device, information, or the local network.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Password Policy >> "Minimum password length" to "14" characters.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000050: The Allow log on locally user right must only be assigned to the Administrators group.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Allow log on locally" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeInteractiveLogonRight" user right, this is a finding. S-1-5-32-544 (Administrators) If an application requires this user right, this would not be a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070).
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Allow log on locally" user right can log on interactively to a system.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Allow log on locally" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000010: Only administrators responsible for the domain controller must have Administrator rights on the system.
This applies to domain controllers. A separate version applies to other systems. Review the Administrators group. Only the appropriate administrator groups or accounts responsible for administration of the system may be members of the group. Standard user accounts must not be members of the local administrator group. If prohibited accounts are members of the local administrators group, this is a finding. If the built-in Administrator account or other required administrative accounts are found on the system, this is not a finding.
Discussion
An account that does not have Administrator duties must not have Administrator rights. Such rights would allow the account to bypass or modify required security restrictions on that machine and make it vulnerable to attack. System administrators must log on to systems using only accounts with the minimum level of authority necessary. Standard user accounts must not be members of the built-in Administrators group.
Fix
Configure the Administrators group to include only administrator groups or accounts that are responsible for the system. Remove any standard user accounts.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-00-000411: The Server Message Block (SMB) v1 protocol must be disabled on the SMB server.
Different methods are available to disable SMBv1 on Windows 2016, if V-73299 is configured, this is NA. If the following registry value does not exist or is not configured as specified, this is a finding: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters\ Value Name: SMB1 Type: REG_DWORD Value: 0x00000000 (0)
Discussion
SMBv1 is a legacy protocol that uses the MD5 algorithm as part of SMB. MD5 is known to be vulnerable to a number of attacks such as collision and preimage attacks as well as not being FIPS compliant.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> MS Security Guide >> "Configure SMBv1 Server" to "Disabled". The system must be restarted for the change to take effect. This policy setting requires the installation of the SecGuide custom templates included with the STIG package. "SecGuide.admx" and "SecGuide.adml" must be copied to the \Windows\PolicyDefinitions and \Windows\PolicyDefinitions\en-US directories respectively.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000080: The Create a pagefile user right must only be assigned to the Administrators group.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Create a pagefile" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeCreatePagefilePrivilege" user right, this is a finding. S-1-5-32-544 (Administrators)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Create a pagefile" user right can change the size of a pagefile, which could affect system performance.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Create a pagefile" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000080: Windows Server 2016 must be configured to audit Account Logon - Credential Validation failures.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Account Logon >> Credential Validation - Failure
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Credential Validation records events related to validation tests on credentials for a user account logon.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Account Logon >> "Audit Credential Validation" with "Failure" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000010: Audit records must be backed up to a different system or media than the system being audited.
Determine if a process to back up log data to a different system or media than the system being audited has been implemented. If it has not, this is a finding.
Discussion
Protection of log data includes assuring the log data is not accidentally lost or deleted. Audit information stored in one location is vulnerable to accidental or incidental deletion or alteration.
Fix
Establish and implement a process for backing up log data to another system or media other than the system being audited.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000120: The Windows Server 2016 system must use an anti-virus program.
Verify an anti-virus solution is installed on the system. The anti-virus solution may be bundled with an approved host-based security solution. If there is no anti-virus solution installed on the system, this is a finding. Verify if Windows Defender is in use or enabled: Open "PowerShell". Enter "get-service | where {$_.DisplayName -Like "*Defender*"} | Select Status,DisplayName” Verify if third-party anti-virus is in use or enabled: Open "PowerShell". Enter "get-service | where {$_.DisplayName -Like "*mcafee*"} | Select Status,DisplayName” Enter "get-service | where {$_.DisplayName -Like "*symantec*"} | Select Status,DisplayName”
Discussion
Malicious software can establish a base on individual desktops and servers. Employing an automated mechanism to detect this type of software will aid in elimination of the software from the operating system.
Fix
If no anti-virus software is in use, install Windows Defender or third-party anti-virus. Open "PowerShell". Enter "Install-WindowsFeature -Name Windows-Defender” For third-party anti-virus, install per anti-virus instructions and disable Windows Defender. Open "PowerShell". Enter “Uninstall-WindowsFeature -Name Windows-Defender”.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-CC-000555: Windows Server 2016 must have PowerShell Transcription enabled.
If the following registry value does not exist or is not configured as specified, this is a finding: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\PowerShell\Transcription\ Value Name: EnableTranscripting Value Type: REG_DWORD Value: 1
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Enabling PowerShell Transcription will record detailed information from the processing of PowerShell commands and scripts. This can provide additional detail when malware has run on a system.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Windows PowerShell >> "Turn on PowerShell Transcription" to "Enabled". Specify the Transcript output directory to point to a Central Log Server or another secure location to prevent user access.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000340: Windows Server 2016 must automatically remove or disable emergency accounts after the crisis is resolved or within 72 hours.
Determine if emergency administrator accounts are used and identify any that exist. If none exist, this is NA. If emergency administrator accounts cannot be configured with an expiration date due to an ongoing crisis, the accounts must be disabled or removed when the crisis is resolved. If emergency administrator accounts have not been configured with an expiration date or have not been disabled or removed following the resolution of a crisis, this is a finding. Domain Controllers: Open "PowerShell". Enter "Search-ADAccount –AccountExpiring | FT Name, AccountExpirationDate". If "AccountExpirationDate" has been defined and is not within 72 hours for an emergency administrator account, this is a finding. Member servers and standalone or nondomain-joined systems: Open "Command Prompt". Run "Net user [username]", where [username] is the name of the emergency account. If "Account expires" has been defined and is not within 72 hours for an emergency administrator account, this is a finding.
Discussion
Emergency administrator accounts are privileged accounts established in response to crisis situations where the need for rapid account activation is required. Therefore, emergency account activation may bypass normal account authorization processes. If these accounts are automatically disabled, system maintenance during emergencies may not be possible, thus adversely affecting system availability. Emergency administrator accounts are different from infrequently used accounts (i.e., local logon accounts used by system administrators when network or normal logon/access is not available). Infrequently used accounts are not subject to automatic termination dates. Emergency accounts are accounts created in response to crisis situations, usually for use by maintenance personnel. The automatic expiration or disabling time period may be extended as needed until the crisis is resolved; however, it must not be extended indefinitely. A permanent account should be established for privileged users who need long-term maintenance accounts. To address access requirements, many operating systems can be integrated with enterprise-level authentication/access mechanisms that meet or exceed access control policy requirements.
Fix
Remove emergency administrator accounts after a crisis has been resolved or configure the accounts to automatically expire within 72 hours. Domain accounts can be configured with an account expiration date under "Account" properties. Local accounts can be configured to expire with the command "Net user [username] /expires:[mm/dd/yyyy]", where username is the name of the temporary user account.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000130: Domain controllers must run on a machine dedicated to that function.
This applies to domain controllers, It is NA for other systems. Review the installed roles the domain controller is supporting. Start "Server Manager". Select "AD DS" in the left pane and the server name under "Servers" to the right. Select "Add (or Remove) Roles and Features" from "Tasks" in the "Roles and Features" section. (Cancel before any changes are made.) Determine if any additional server roles are installed. A basic domain controller setup will include the following: - Active Directory Domain Services - DNS Server - File and Storage Services If any roles not requiring installation on a domain controller are installed, this is a finding. A Domain Name System (DNS) server integrated with the directory server (e.g., AD-integrated DNS) is an acceptable application. However, the DNS server must comply with the DNS STIG security requirements. Run "Programs and Features". Review installed applications. If any applications are installed that are not required for the domain controller, this is a finding.
Discussion
Executing application servers on the same host machine with a directory server may substantially weaken the security of the directory server. Web or database server applications usually require the addition of many programs and accounts, increasing the attack surface of the computer. Some applications require the addition of privileged accounts, providing potential sources of compromise. Some applications (such as Microsoft Exchange) may require the use of network ports or services conflicting with the directory server. In this case, non-standard ports might be selected, and this could interfere with intrusion detection or prevention services.
Fix
Remove additional roles or applications such as web, database, and email from the domain controller.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000410: The Server Message Block (SMB) v1 protocol must be uninstalled.
Different methods are available to disable SMBv1 on Windows 2016. This is the preferred method, however if V-78123 and V-78125 are configured, this is NA. Open "Windows PowerShell" with elevated privileges (run as administrator). Enter "Get-WindowsFeature -Name FS-SMB1". If "Installed State" is "Installed", this is a finding. An Installed State of "Available" or "Removed" is not a finding.
Discussion
SMBv1 is a legacy protocol that uses the MD5 algorithm as part of SMB. MD5 is known to be vulnerable to a number of attacks such as collision and preimage attacks and is not FIPS compliant.
Fix
Uninstall the SMBv1 protocol. Open "Windows PowerShell" with elevated privileges (run as administrator). Enter "Uninstall-WindowsFeature -Name FS-SMB1 -Restart". (Omit the Restart parameter if an immediate restart of the system cannot be done.) Alternately: Start "Server Manager". Select the server with the feature. Scroll down to "ROLES AND FEATURES" in the right pane. Select "Remove Roles and Features" from the drop-down "TASKS" list. Select the appropriate server on the "Server Selection" page and click "Next". Deselect "SMB 1.0/CIFS File Sharing Support" on the "Features" page. Click "Next" and "Remove" as prompted.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000360: Windows Server 2016 must be configured to audit Privilege Use - Sensitive Privilege Use failures.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Privilege Use >> Sensitive Privilege Use - Failure
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Sensitive Privilege Use records events related to use of sensitive privileges, such as "Act as part of the operating system" or "Debug programs". Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000064-GPOS-00033, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Privilege Use >> "Audit Sensitive Privilege Use" with "Failure" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000300: The Restore files and directories user right must only be assigned to the Administrators group.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Restore files and directories" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeRestorePrivilege" user right, this is a finding. S-1-5-32-544 (Administrators) If an application requires this user right, this would not be a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070).
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Restore files and directories" user right can circumvent file and directory permissions and could allow access to sensitive data. It could also be used to overwrite more current data.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Restore files and directories" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000030: WDigest Authentication must be disabled on Windows Server 2016.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\SecurityProviders\Wdigest\ Value Name: UseLogonCredential Type: REG_DWORD Value: 0x00000000 (0)
Discussion
When the WDigest Authentication protocol is enabled, plain-text passwords are stored in the Local Security Authority Subsystem Service (LSASS), exposing them to theft. WDigest is disabled by default in Windows Server 2016. This setting ensures this is enforced.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> MS Security Guide >> "WDigest Authentication (disabling may require KB2871997)" to "Disabled". This policy setting requires the installation of the SecGuide custom templates included with the STIG package. "SecGuide.admx" and " SecGuide.adml" must be copied to the \Windows\PolicyDefinitions and \Windows\PolicyDefinitions\en-US directories respectively.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000100: The Create global objects user right must only be assigned to Administrators, Service, Local Service, and Network Service.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Create global objects" user right, this is a finding. - Administrators - Service - Local Service - Network Service For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeCreateGlobalPrivilege" user right, this is a finding. S-1-5-32-544 (Administrators) S-1-5-6 (Service) S-1-5-19 (Local Service) S-1-5-20 (Network Service) If an application requires this user right, this would not be a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070).
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Create global objects" user right can create objects that are available to all sessions, which could affect processes in other users' sessions.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Create global objects" to include only the following accounts or groups: - Administrators - Service - Local Service - Network Service
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000180: The network selection user interface (UI) must not be displayed on the logon screen.
Verify the registry value below. If it does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\System\ Value Name: DontDisplayNetworkSelectionUI Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Enabling interaction with the network selection UI allows users to change connections to available networks without signing in to Windows.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> System >> Logon >> "Do not display network selection UI" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000500: User Account Control must be configured to detect application installations and prompt for elevation.
UAC requirements are NA for Server Core installations (this is the default installation option for Windows Server 2016 versus Server with Desktop Experience) as well as Nano Server. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ Value Name: EnableInstallerDetection Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
User Account Control (UAC) is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting requires Windows to respond to application installation requests by prompting for credentials.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "User Account Control: Detect application installations and prompt for elevation" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000160: Windows Server 2016 must be configured to audit Detailed Tracking - Plug and Play Events successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*" Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Detailed Tracking >> Plug and Play Events - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Plug and Play activity records events related to the successful connection of external devices.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Detailed Tracking >> "Audit PNP Activity" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000440: Windows Server 2016 must be configured to audit System - System Integrity successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. System >> System Integrity - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. System Integrity records events related to violations of integrity to the security subsystem. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000471-GPOS-00215, SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> System >> "Audit System Integrity" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000380: Local drives must be prevented from sharing with Remote Desktop Session Hosts.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services\ Value Name: fDisableCdm Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Preventing users from sharing the local drives on their client computers with Remote Session Hosts that they access helps reduce possible exposure of sensitive data.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Remote Desktop Services >> Remote Desktop Session Host >> Device and Resource Redirection >> "Do not allow drive redirection" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000270: AutoPlay must be disabled for all drives.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\ Value Name: NoDriveTypeAutoRun Type: REG_DWORD Value: 0x000000ff (255)
Discussion
Allowing AutoPlay to execute may introduce malicious code to a system. AutoPlay begins reading from a drive as soon media is inserted into the drive. As a result, the setup file of programs or music on audio media may start. By default, AutoPlay is disabled on removable drives, such as the floppy disk drive (but not the CD-ROM drive) and on network drives. Enabling this policy disables AutoPlay on all drives.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> AutoPlay Policies >> "Turn off AutoPlay" to "Enabled" with "All Drives" selected.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-SO-000090: The setting Domain member: Digitally encrypt secure channel data (when possible) must be configured to enabled.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\Netlogon\Parameters\ Value Name: SealSecureChannel Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Requests sent on the secure channel are authenticated, and sensitive information (such as passwords) is encrypted, but not all information is encrypted. If this policy is enabled, outgoing secure channel traffic will be encrypted. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Domain member: Digitally encrypt secure channel data (when possible)" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000090: Windows Server 2016 must employ a deny-all, permit-by-exception policy to allow the execution of authorized software programs.
Verify the operating system employs a deny-all, permit-by-exception policy to allow the execution of authorized software programs. If an application allowlisting program is not in use on the system, this is a finding. Configuration of allowlisting applications will vary by the program. AppLocker is an allowlisting application built into Windows Server. A deny-by-default implementation is initiated by enabling any AppLocker rules within a category, only allowing what is specified by defined rules. If AppLocker is used, perform the following to view the configuration of AppLocker: Open "PowerShell". If the AppLocker PowerShell module has not been imported previously, execute the following first: Import-Module AppLocker Execute the following command, substituting [c:\temp\file.xml] with a location and file name appropriate for the system: Get-AppLockerPolicy -Effective -XML > c:\temp\file.xml This will produce an xml file with the effective settings that can be viewed in a browser or opened in a program such as Excel for review. Implementation guidance for AppLocker is available at the following link: https://docs.microsoft.com/en-us/windows/security/threat-protection/windows-defender-application-control/applocker/applocker-policies-deployment-guide
Discussion
Using an allowlist provides a configuration management method to allow the execution of only authorized software. Using only authorized software decreases risk by limiting the number of potential vulnerabilities. The organization must identify authorized software programs and only permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as allowlisting.
Fix
Configure an application allowlisting program to employ a deny-all, permit-by-exception policy to allow the execution of authorized software programs. Configuration of allowlisting applications will vary by the program. AppLocker is an allowlisting application built into Windows Server. If AppLocker is used, it is configured through group policy in Computer Configuration >> Windows Settings >> Security Settings >> Application Control Policies >> AppLocker. Implementation guidance for AppLocker is available at the following link: https://docs.microsoft.com/en-us/windows/security/threat-protection/windows-defender-application-control/applocker/applocker-policies-deployment-guide
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000210: Users must be prompted to authenticate when the system wakes from sleep (on battery).
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Power\PowerSettings\0e796bdb-100d-47d6-a2d5-f7d2daa51f51\ Value Name: DCSettingIndex Type: REG_DWORD Value: 0x00000001 (1)
Discussion
A system that does not require authentication when resuming from sleep may provide access to unauthorized users. Authentication must always be required when accessing a system. This setting ensures users are prompted for a password when the system wakes from sleep (on battery).
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> System >> Power Management >> Sleep Settings >> "Require a password when a computer wakes (on battery)" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000250: The Lock pages in memory user right must not be assigned to any groups or accounts.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups are granted the "Lock pages in memory" user right, this is a finding. For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs are granted the "SeLockMemoryPrivilege" user right, this is a finding. If an application requires this user right, this would not be a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070).
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Lock pages in memory" user right allows physical memory to be assigned to processes, which could cause performance issues or a denial of service.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Lock pages in memory" to be defined but containing no entries (blank).
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000390: Remote Desktop Services must always prompt a client for passwords upon connection.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services\ Value Name: fPromptForPassword Type: REG_DWORD Value: 0x00000001 (1)
Discussion
This setting controls the ability of users to supply passwords automatically as part of their remote desktop connection. Disabling this setting would allow anyone to use the stored credentials in a connection item to connect to the terminal server. Satisfies: SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00156
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Remote Desktop Services >> Remote Desktop Session Host >> Security >> "Always prompt for password upon connection" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000300: Windows Server 2016 must be configured to audit Object Access - Removable Storage failures.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Object Access >> Removable Storage - Failure Virtual machines or systems that use network attached storage may generate excessive audit events for secondary virtual drives or the network attached storage when this setting is enabled. This may be set to Not Configured in such cases and would not be a finding.
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Removable Storage auditing under Object Access records events related to access attempts on file system objects on removable storage devices.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Object Access >> "Audit Removable Storage" with "Failure" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000230: Passwords must be configured to expire.
Review the password never expires status for enabled user accounts. Open "PowerShell". Domain Controllers: Enter "Search-ADAccount -PasswordNeverExpires -UsersOnly | FT Name, PasswordNeverExpires, Enabled". Exclude application accounts, disabled accounts (e.g., DefaultAccount, Guest), and the krbtgt account. If any enabled user accounts are returned with a "PasswordNeverExpires" status of "True", this is a finding. Member servers and standalone or nondomain-joined systems: Enter 'Get-CimInstance -Class Win32_Useraccount -Filter "PasswordExpires=False and LocalAccount=True" | FT Name, PasswordExpires, Disabled, LocalAccount'. Exclude application accounts and disabled accounts (e.g., DefaultAccount, Guest). If any enabled user accounts are returned with a "PasswordExpires" status of "False", this is a finding.
Discussion
Passwords that do not expire or are reused increase the exposure of a password with greater probability of being discovered or cracked.
Fix
Configure all enabled user account passwords to expire. Uncheck "Password never expires" for all enabled user accounts in Active Directory Users and Computers for domain accounts and Users in Computer Management for member servers and standalone or nondomain-joined systems. Document any exceptions with the ISSO.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000050: Members of the Backup Operators group must have separate accounts for backup duties and normal operational tasks.
If no accounts are members of the Backup Operators group, this is NA. Verify users with accounts in the Backup Operators group have a separate user account for backup functions and for performing normal user tasks. If users with accounts in the Backup Operators group do not have separate accounts for backup functions and standard user functions, this is a finding.
Discussion
Backup Operators are able to read and write to any file in the system, regardless of the rights assigned to it. Backup and restore rights permit users to circumvent the file access restrictions present on NTFS disk drives for backup and restore purposes. Members of the Backup Operators group must have separate logon accounts for performing backup duties.
Fix
Ensure each member of the Backup Operators group has separate accounts for backup functions and standard user functions.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000290: Protection methods such as TLS, encrypted VPNs, or IPsec must be implemented if the data owner has a strict requirement for ensuring data integrity and confidentiality is maintained at every step of the data transfer and handling process.
If the data owner has a strict requirement for ensuring data integrity and confidentiality is maintained at every step of the data transfer and handling process, verify protection methods such as TLS, encrypted VPNs, or IPsec have been implemented. If protection methods have not been implemented, this is a finding.
Discussion
Information can be either unintentionally or maliciously disclosed or modified during preparation for transmission, for example, during aggregation, at protocol transformation points, and during packing/unpacking. These unauthorized disclosures or modifications compromise the confidentiality or integrity of the information. Ensuring the confidentiality of transmitted information requires the operating system to take measures in preparing information for transmission. This can be accomplished via access control and encryption. Use of this requirement will be limited to situations where the data owner has a strict requirement for ensuring data integrity and confidentiality is maintained at every step of the data transfer and handling process. When transmitting data, operating systems need to support transmission protection mechanisms such as TLS, encrypted VPNs, or IPsec. Satisfies: SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190
Fix
Configure protection methods such as TLS, encrypted VPNs, or IPsec when the data owner has a strict requirement for ensuring data integrity and confidentiality is maintained at every step of the data transfer and handling process.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
Old Rule ID 'SV-224844r569186_rule'
WN16-CC-000240: The Application Compatibility Program Inventory must be prevented from collecting data and sending the information to Microsoft.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\AppCompat\ Value Name: DisableInventory Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Some features may communicate with the vendor, sending system information or downloading data or components for the feature. Turning off this capability will prevent potentially sensitive information from being sent outside the enterprise and will prevent uncontrolled updates to the system. This setting will prevent the Program Inventory from collecting data about a system and sending the information to Microsoft.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Application Compatibility >> "Turn off Inventory Collector" to "Enabled".
Rating Info
DISA Cat III. NIST impact 2.
Expert Comment
None
WN16-SO-000230: The setting Microsoft network server: Digitally sign communications (always) must be configured to Enabled.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\LanManServer\Parameters\ Value Name: RequireSecuritySignature Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
The server message block (SMB) protocol provides the basis for many network operations. Digitally signed SMB packets aid in preventing man-in-the-middle attacks. If this policy is enabled, the SMB server will only communicate with an SMB client that performs SMB packet signing. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Microsoft network server: Digitally sign communications (always)" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000030: The Act as part of the operating system user right must not be assigned to any groups or accounts.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups (to include administrators), are granted the "Act as part of the operating system" user right, this is a finding. For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs are granted the "SeTcbPrivilege" user right, this is a finding. If an application requires this user right, this would not be a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070). Passwords for accounts with this user right must be protected as highly privileged accounts.
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Act as part of the operating system" user right can assume the identity of any user and gain access to resources that the user is authorized to access. Any accounts with this right can take complete control of a system.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Act as part of the operating system" to be defined but containing no entries (blank).
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-SO-000180: The Smart Card removal option must be configured to Force Logoff or Lock Workstation.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\ Value Name: scremoveoption Value Type: REG_SZ Value: 1 (Lock Workstation) or 2 (Force Logoff) If configuring this on servers causes issues, such as terminating users' remote sessions, and the organization has a policy in place that any other sessions on the servers, such as administrative console logons, are manually locked or logged off when unattended or not in use, this would be acceptable. This must be documented with the ISSO.
Discussion
Unattended systems are susceptible to unauthorized use and must be locked. Configuring a system to lock when a smart card is removed will ensure the system is inaccessible when unattended.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Interactive logon: Smart card removal behavior" to "Lock Workstation" or "Force Logoff".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000420: Users must be required to enter a password to access private keys stored on the computer.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Cryptography\ Value Name: ForceKeyProtection Type: REG_DWORD Value: 0x00000002 (2)
Discussion
If the private key is discovered, an attacker can use the key to authenticate as an authorized user and gain access to the network infrastructure. The cornerstone of the PKI is the private key used to encrypt or digitally sign information. If the private key is stolen, this will lead to the compromise of the authentication and non-repudiation gained through PKI because the attacker can use the private key to digitally sign documents and pretend to be the authorized user. Both the holders of a digital certificate and the issuing authority must protect the computers, storage devices, or whatever they use to keep the private keys.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "System cryptography: Force strong key protection for user keys stored on the computer" to "User must enter a password each time they use a key".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000400: The TFTP Client must not be installed.
Open "PowerShell". Enter "Get-WindowsFeature | Where Name -eq TFTP-Client". If "Installed State" is "Installed", this is a finding. An Installed State of "Available" or "Removed" is not a finding.
Discussion
Unnecessary services increase the attack surface of a system. Some of these services may not support required levels of authentication or encryption or may provide unauthorized access to the system.
Fix
Uninstall the "TFTP Client" feature. Start "Server Manager". Select the server with the feature. Scroll down to "ROLES AND FEATURES" in the right pane. Select "Remove Roles and Features" from the drop-down "TASKS" list. Select the appropriate server on the "Server Selection" page and click "Next". Deselect "TFTP Client" on the "Features" page. Click "Next" and "Remove" as prompted.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000490: PowerShell script block logging must be enabled.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\ Policies\Microsoft\Windows\PowerShell\ScriptBlockLogging\ Value Name: EnableScriptBlockLogging Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Enabling PowerShell script block logging will record detailed information from the processing of PowerShell commands and scripts. This can provide additional detail when malware has run on a system.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Windows PowerShell >> "Turn on PowerShell Script Block Logging" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000370: The Peer Name Resolution Protocol must not be installed.
Open "PowerShell". Enter "Get-WindowsFeature | Where Name -eq PNRP". If "Installed State" is "Installed", this is a finding. An Installed State of "Available" or "Removed" is not a finding.
Discussion
Unnecessary services increase the attack surface of a system. Some of these services may not support required levels of authentication or encryption or may provide unauthorized access to the system.
Fix
Uninstall the "Peer Name Resolution Protocol" feature. Start "Server Manager". Select the server with the feature. Scroll down to "ROLES AND FEATURES" in the right pane. Select "Remove Roles and Features" from the drop-down "TASKS" list. Select the appropriate server on the "Server Selection" page and click "Next". Deselect "Peer Name Resolution Protocol" on the "Features" page. Click "Next" and "Remove" as prompted.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000120: Windows Server 2016 must be configured to audit Account Management - Security Group Management successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Account Management >> Security Group Management - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Security Group Management records events such as creating, deleting, or changing security groups, including changes in group members. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000476-GPOS-00221
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Account Management >> "Audit Security Group Management" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000350: The Fax Server role must not be installed.
Open "PowerShell". Enter "Get-WindowsFeature | Where Name -eq Fax". If "Installed State" is "Installed", this is a finding. An Installed State of "Available" or "Removed" is not a finding.
Discussion
Unnecessary services increase the attack surface of a system. Some of these services may not support required levels of authentication or encryption or may provide unauthorized access to the system.
Fix
Uninstall the "Fax Server" role. Start "Server Manager". Select the server with the role. Scroll down to "ROLES AND FEATURES" in the right pane. Select "Remove Roles and Features" from the drop-down "TASKS" list. Select the appropriate server on the "Server Selection" page and click "Next". Deselect "Fax Server" on the "Roles" page. Click "Next" and "Remove" as prompted.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-MS-000030: Local users on domain-joined computers must not be enumerated.
This applies to member servers. For domain controllers and standalone or nondomain-joined systems, this is NA. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\System\ Value Name: EnumerateLocalUsers Type: REG_DWORD Value: 0x00000000 (0)
Discussion
The username is one part of logon credentials that could be used to gain access to a system. Preventing the enumeration of users limits this information to authorized personnel.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> System >> Logon >> "Enumerate local users on domain-joined computers" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000530: The Windows Remote Management (WinRM) service must not use Basic authentication.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\WinRM\Service\ Value Name: AllowBasic Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Basic authentication uses plain-text passwords that could be used to compromise a system. Disabling Basic authentication will reduce this potential.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Windows Remote Management (WinRM) >> WinRM Service >> "Allow Basic authentication" to "Disabled".
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-00-000140: Servers must have a host-based intrusion detection or prevention system.
Determine whether there is a HIDS or HIPS on each server. If the HIPS component of ESS is installed and active on the host and the alerts of blocked activity are being logged and monitored, this meets the requirement. A HIDS device is not required on a system that has the role as the Network Intrusion Device (NID). However, this exception needs to be documented with the ISSO. If a HIDS is not installed on the system, this is a finding.
Discussion
A properly configured Host-based Intrusion Detection System (HIDS) or Host-based Intrusion Prevention System (HIPS) provides another level of defense against unauthorized access to critical servers. With proper configuration and logging enabled, such a system can stop and/or alert for many attempts to gain unauthorized access to resources.
Fix
Install a HIDS or HIPS on each server.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000030: Windows Server 2016 built-in administrator account must be renamed.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options. If the value for "Accounts: Rename administrator account" is not set to a value other than "Administrator", this is a finding. For server core installations, run the following command: Secedit /Export /Areas SecurityPolicy /CFG C:\Path\FileName.Txt If "NewAdministratorName" is not something other than "Administrator" in the file, this is a finding.
Discussion
The built-in administrator account is a well-known account subject to attack. Renaming this account to an unidentified name improves the protection of this account and the system.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Accounts: Rename administrator account" to a name other than "Administrator".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000110: Windows Server 2016 virtualization-based security must be enabled with the platform security level configured to Secure Boot or Secure Boot with DMA Protection.
For standalone or nondomain-joined systems, this is NA. Open "PowerShell" with elevated privileges (run as administrator). Enter the following: "Get-CimInstance -ClassName Win32_DeviceGuard -Namespace root\Microsoft\Windows\DeviceGuard" If "RequiredSecurityProperties" does not include a value of "2" indicating "Secure Boot" (e.g., "{1, 2}"), this is a finding. If "Secure Boot and DMA Protection" is configured, "3" will also be displayed in the results (e.g., "{1, 2, 3}"). If "VirtualizationBasedSecurityStatus" is not a value of "2" indicating "Running", this is a finding. Alternately: Run "System Information". Under "System Summary", verify the following: If "Device Guard Virtualization based security" does not display "Running", this is a finding. If "Device Guard Required Security Properties" does not display "Base Virtualization Support, Secure Boot", this is a finding. If "Secure Boot and DMA Protection" is configured, "DMA Protection" will also be displayed (e.g., "Base Virtualization Support, Secure Boot, DMA Protection"). The policy settings referenced in the Fix section will configure the following registry values. However, due to hardware requirements, the registry values alone do not ensure proper function. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\DeviceGuard\ Value Name: EnableVirtualizationBasedSecurity Value Type: REG_DWORD Value: 0x00000001 (1) Value Name: RequirePlatformSecurityFeatures Value Type: REG_DWORD Value: 0x00000001 (1) (Secure Boot only) or 0x00000003 (3) (Secure Boot and DMA Protection) A Microsoft TechNet article on Credential Guard, including system requirement details, can be found at the following link: https://technet.microsoft.com/itpro/windows/keep-secure/credential-guard
Discussion
Virtualization-based security (VBS) provides the platform for the additional security features Credential Guard and virtualization-based protection of code integrity. Secure Boot is the minimum security level, with DMA protection providing additional memory protection. DMA Protection requires a CPU that supports input/output memory management unit (IOMMU).
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> System >> Device Guard >> "Turn On Virtualization Based Security" to "Enabled" with "Secure Boot" or "Secure Boot and DMA Protection" selected. A Microsoft TechNet article on Credential Guard, including system requirement details, can be found at the following link: https://technet.microsoft.com/itpro/windows/keep-secure/credential-guard
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-MS-000420: The "Enable computer and user accounts to be trusted for delegation" user right must not be assigned to any groups or accounts on member servers.
This applies to member servers and standalone or nondomain-joined systems. A separate version applies to domain controllers. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups are granted the "Enable computer and user accounts to be trusted for delegation" user right, this is a finding. For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs are granted the "SeEnableDelegationPrivilege" user right, this is a finding.
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Enable computer and user accounts to be trusted for delegation" user right allows the "Trusted for Delegation" setting to be changed. This could allow unauthorized users to impersonate other users.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Enable computer and user accounts to be trusted for delegation" to be defined but containing no entries (blank).
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000350: The Add workstations to domain user right must only be assigned to the Administrators group.
This applies to domain controllers. It is NA for other systems. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Add workstations to domain" right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeMachineAccountPrivilege" user right, this is a finding. S-1-5-32-544 (Administrators)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Add workstations to domain" right may add computers to a domain. This could result in unapproved or incorrectly configured systems being added to a domain.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Add workstations to domain" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000350: Turning off File Explorer heap termination on corruption must be disabled.
The default behavior is for File Explorer heap termination on corruption to be enabled. If the registry Value Name below does not exist, this is not a finding. If it exists and is configured with a value of "0", this is not a finding. If it exists and is configured with a value of "1", this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\Explorer\ Value Name: NoHeapTerminationOnCorruption Value Type: REG_DWORD Value: 0x00000000 (0) (or if the Value Name does not exist)
Discussion
Legacy plug-in applications may continue to function when a File Explorer session has become corrupt. Disabling this feature will prevent this.
Fix
The default behavior is for File Explorer heap termination on corruption to be disabled. If this needs to be corrected, configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> File Explorer >> "Turn off heap termination on corruption" to "Not Configured" or "Disabled".
Rating Info
DISA Cat III. NIST impact 2.
Expert Comment
None
WN16-DC-000120: Data files owned by users must be on a different logical partition from the directory server data files.
This applies to domain controllers. It is NA for other systems. Run "Regedit". Navigate to "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Parameters". Note the directory locations in the values for "DSA Database file". Open "Command Prompt". Enter "net share". Note the logical drive(s) or file system partition for any organization-created data shares. Ignore system shares (e.g., NETLOGON, SYSVOL, and administrative shares ending in $). User shares that are hidden (ending with $) should not be ignored. If user shares are located on the same logical partition as the directory server data files, this is a finding.
Discussion
When directory service data files, especially for directories used for identification, authentication, or authorization, reside on the same logical partition as user-owned files, the directory service data may be more vulnerable to unauthorized access or other availability compromises. Directory service and user-owned data files sharing a partition may be configured with less restrictive permissions in order to allow access to the user data. The directory service may be vulnerable to a denial of service attack when user-owned files on a common partition are expanded to an extent preventing the directory service from acquiring more space for directory or audit data.
Fix
Move shares used to store files owned by users to a different logical partition than the directory server data files.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000412: The Server Message Block (SMB) v1 protocol must be disabled on the SMB client.
Different methods are available to disable SMBv1 on Windows 2016, if V-73299 is configured, this is NA. If the following registry value is not configured as specified, this is a finding: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\mrxsmb10\ Value Name: Start Type: REG_DWORD Value: 0x00000004 (4)
Discussion
SMBv1 is a legacy protocol that uses the MD5 algorithm as part of SMB. MD5 is known to be vulnerable to a number of attacks such as collision and preimage attacks as well as not being FIPS compliant.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> MS Security Guide >> "Configure SMBv1 client driver" to "Enabled" with "Disable driver (recommended)" selected for "Configure MrxSmb10 driver". The system must be restarted for the changes to take effect. This policy setting requires the installation of the SecGuide custom templates included with the STIG package. "SecGuide.admx" and "SecGuide.adml" must be copied to the \Windows\PolicyDefinitions and \Windows\PolicyDefinitions\en-US directories respectively.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000290: Windows Server 2016 must be configured to prevent anonymous users from having the same permissions as the Everyone group.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\Lsa\ Value Name: EveryoneIncludesAnonymous Value Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Access by anonymous users must be restricted. If this setting is enabled, anonymous users have the same rights and permissions as the built-in Everyone group. Anonymous users must not have these permissions or rights.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network access: Let everyone permissions apply to anonymous users" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000400: Session security for NTLM SSP-based clients must be configured to require NTLMv2 session security and 128-bit encryption.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\Lsa\MSV1_0\ Value Name: NTLMMinClientSec Value Type: REG_DWORD Value: 0x20080000 (537395200)
Discussion
Microsoft has implemented a variety of security support providers for use with Remote Procedure Call (RPC) sessions. All of the options must be enabled to ensure the maximum security level.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network security: Minimum session security for NTLM SSP based (including secure RPC) clients" to "Require NTLMv2 session security" and "Require 128-bit encryption" (all options selected).
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000320: Domain controllers must require LDAP access signing.
This applies to domain controllers. It is NA for other systems. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\NTDS\Parameters\ Value Name: LDAPServerIntegrity Value Type: REG_DWORD Value: 0x00000002 (2)
Discussion
Unsigned network traffic is susceptible to man-in-the-middle attacks, where an intruder captures packets between the server and the client and modifies them before forwarding them to the client. In the case of an LDAP server, this means that an attacker could cause a client to make decisions based on false records from the LDAP directory. The risk of an attacker pulling this off can be decreased by implementing strong physical security measures to protect the network infrastructure. Furthermore, implementing Internet Protocol security (IPsec) authentication header mode (AH), which performs mutual authentication and packet integrity for Internet Protocol (IP) traffic, can make all types of man-in-the-middle attacks extremely difficult. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Domain controller: LDAP server signing requirements" to "Require signing".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000190: The Active Directory Infrastructure object must be configured with proper audit settings.
This applies to domain controllers. It is NA for other systems. Review the auditing configuration for Infrastructure object. Open "Active Directory Users and Computers" (available from various menus or run "dsa.msc"). Ensure "Advanced Features" is selected in the "View" menu. Select the domain being reviewed in the left pane. Right-click the "Infrastructure" object in the right pane and select "Properties". Select the "Security" tab. Select the "Advanced" button and then the "Auditing" tab. If the audit settings on the Infrastructure object are not at least as inclusive as those below, this is a finding. Type - Fail Principal - Everyone Access - Full Control Inherited from - None The success types listed below are defaults. Where Special is listed in the summary screens for Access, detailed Permissions are provided for reference. Various Properties selections may also exist by default. Type - Success Principal - Everyone Access - Special Inherited from - None (Access - Special = Permissions: Write all properties, All extended rights, Change infrastructure master) Two instances with the following summary information will be listed. Type - Success Principal - Everyone Access - (blank) Inherited from - (CN of domain)
Discussion
When inappropriate audit settings are configured for directory service database objects, it may be possible for a user or process to update the data without generating any tracking data. The impact of missing audit data is related to the type of object. A failure to capture audit data for objects used by identification, authentication, or authorization functions could degrade or eliminate the ability to track changes to access policy for systems or data. For Active Directory (AD), there are a number of critical object types in the domain naming context of the AD database for which auditing is essential. This includes the Infrastructure object. Because changes to these objects can significantly impact access controls or the availability of systems, the absence of auditing data makes it impossible to identify the source of changes that impact the confidentiality, integrity, and availability of data and systems throughout an AD domain. The lack of proper auditing can result in insufficient forensic evidence needed to investigate an incident and prosecute the intruder. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Open "Active Directory Users and Computers" (available from various menus or run "dsa.msc"). Ensure "Advanced Features" is selected in the "View" menu. Select the domain being reviewed in the left pane. Right-click the "Infrastructure" object in the right pane and select "Properties". Select the "Security" tab. Select the "Advanced" button and then the "Auditing" tab. Configure the audit settings for Infrastructure object to include the following. Type - Fail Principal - Everyone Access - Full Control Inherited from - None The success types listed below are defaults. Where Special is listed in the summary screens for Access, detailed Permissions are provided for reference. Various Properties selections may also exist by default. Type - Success Principal - Everyone Access - Special Inherited from - None (Access - Special = Permissions: Write all properties, All extended rights, Change infrastructure master) Two instances with the following summary information will be listed. Type - Success Principal - Everyone Access - (blank) Inherited from - (CN of domain)
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000240: System files must be monitored for unauthorized changes.
Determine if the system is monitored for unauthorized changes to system files (e.g., *.exe, *.bat, *.com, *.cmd, and *.dll) against a baseline on a weekly basis. If system files are not being monitored for unauthorized changes, this is a finding. An approved and properly configured solution will contain both a list of baselines that includes all system file locations and a file comparison task that is scheduled to run at least weekly.
Discussion
Monitoring system files for changes against a baseline on a regular basis may help detect the possible introduction of malicious code on a system.
Fix
Monitor the system for unauthorized changes to system files (e.g., *.exe, *.bat, *.com, *.cmd, and *.dll) against a baseline on a weekly basis. This can be done with the use of various monitoring tools.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000290: The Profile single process user right must only be assigned to the Administrators group.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Profile single process" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeProfileSingleProcessPrivilege" user right, this is a finding. S-1-5-32-544 (Administrators)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Profile single process" user right can monitor non-system processes performance. An attacker could use this to identify processes to attack.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Profile single process" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000110: Domain-created Active Directory Organizational Unit (OU) objects must have proper access control permissions.
This applies to domain controllers. It is NA for other systems. Review the permissions on domain-defined OUs. Open "Active Directory Users and Computers" (available from various menus or run "dsa.msc"). Ensure "Advanced Features" is selected in the "View" menu. For each OU that is defined (folder in folder icon) excluding the Domain Controllers OU: Right-click the OU and select "Properties". Select the "Security" tab. If the permissions on the OU are not at least as restrictive as those below, this is a finding. The permissions shown are at the summary level. More detailed permissions can be viewed by selecting the "Advanced" button, the desired Permission entry, and the "Edit" or "View" button. Except where noted otherwise, the special permissions may include a wide range of permissions and properties and are acceptable for this requirement. CREATOR OWNER - Special permissions Self - Special permissions Authenticated Users - Read, Special permissions The Special permissions for Authenticated Users are Read type. If detailed permissions include any Create, Delete, Modify, or Write Permissions or Properties, this is a finding. SYSTEM - Full Control Domain Admins - Full Control Enterprise Admins - Full Control Key Admins - Special permissions Enterprise Key Admins - Special permissions Administrators - Read, Write, Create all child objects, Generate resultant set of policy (logging), Generate resultant set of policy (planning), Special permissions Pre-Windows 2000 Compatible Access - Special permissions The Special permissions for Pre-Windows 2000 Compatible Access are for Read types. If detailed permissions include any Create, Delete, Modify, or Write Permissions or Properties, this is a finding. ENTERPRISE DOMAIN CONTROLLERS - Read, Special permissions If an ISSO-approved distributed administration model (help desk or other user support staff) is implemented, permissions above Read may be allowed for groups documented by the ISSO. If any OU with improper permissions includes identification or authentication data (e.g., accounts, passwords, or password hash data) used by systems to determine access control, the severity is CAT I (e.g., OUs that include user accounts, including service/application accounts). If an OU with improper permissions does not include identification and authentication data used by systems to determine access control, the severity is CAT II (e.g., Workstation, Printer OUs).
Discussion
When directory service database objects do not have appropriate access control permissions, it may be possible for malicious users to create, read, update, or delete the objects and degrade or destroy the integrity of the data. When the directory service is used for identification, authentication, or authorization functions, a compromise of the database objects could lead to a compromise of all systems that rely on the directory service. For Active Directory, the OU objects require special attention. In a distributed administration model (i.e., help desk), OU objects are more likely to have access permissions changed from the secure defaults. If inappropriate access permissions are defined for OU objects, it could allow an intruder to add or delete users in the OU. This could result in unauthorized access to data or a denial of service to authorized users.
Fix
Maintain the permissions on domain-defined OUs to be at least as restrictive as the defaults below. Document any additional permissions above Read with the ISSO if an approved distributed administration model (help desk or other user support staff) is implemented. CREATOR OWNER - Special permissions Self - Special permissions Authenticated Users - Read, Special permissions The special permissions for Authenticated Users are Read type. SYSTEM - Full Control Domain Admins - Full Control Enterprise Admins - Full Control Key Admins - Special permissions Enterprise Key Admins - Special permissions Administrators - Read, Write, Create all child objects, Generate resultant set of policy (logging), Generate resultant set of policy (planning), Special permissions Pre-Windows 2000 Compatible Access - Special permissions The special permissions for Pre-Windows 2000 Compatible Access are for Read types. ENTERPRISE DOMAIN CONTROLLERS - Read, Special permissions
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-CC-000400: The Remote Desktop Session Host must require secure Remote Procedure Call (RPC) communications.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services\ Value Name: fEncryptRPCTraffic Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Allowing unsecure RPC communication exposes the system to man-in-the-middle attacks and data disclosure attacks. A man-in-the-middle attack occurs when an intruder captures packets between a client and server and modifies them before allowing the packets to be exchanged. Usually the attacker will modify the information in the packets in an attempt to cause either the client or server to reveal sensitive information.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Remote Desktop Services >> Remote Desktop Session Host >> Security >> "Require secure RPC communication" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000520: User Account Control must run all administrators in Admin Approval Mode, enabling UAC.
UAC requirements are NA for Server Core installations (this is the default installation option for Windows Server 2016 versus Server with Desktop Experience) as well as Nano Server. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ Value Name: EnableLUA Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
User Account Control (UAC) is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting enables UAC. Satisfies: SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00156
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "User Account Control: Run all administrators in Admin Approval Mode" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AC-000050: Windows Server 2016 maximum password age must be configured to 60 days or less.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Password Policy. If the value for the "Maximum password age" is greater than "60" days, this is a finding. If the value is set to "0" (never expires), this is a finding. For server core installations, run the following command: Secedit /Export /Areas SecurityPolicy /CFG C:\Path\FileName.Txt If "MaximumPasswordAge" is greater than "60" or equal to "0" in the file, this is a finding.
Discussion
The longer a password is in use, the greater the opportunity for someone to gain unauthorized knowledge of the passwords. Scheduled changing of passwords hinders the ability of unauthorized system users to crack passwords and gain access to a system.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Password Policy >> "Maximum password age" to "60" days or less (excluding "0", which is unacceptable).
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-PK-000010: The DoD Root CA certificates must be installed in the Trusted Root Store.
The certificates and thumbprints referenced below apply to unclassified systems; refer to PKE documentation for other networks. Open "Windows PowerShell" as an administrator. Execute the following command: Get-ChildItem -Path Cert:Localmachine\root | Where Subject -Like "*DoD*" | FL Subject, Thumbprint, NotAfter If the following certificate "Subject" and "Thumbprint" information is not displayed, this is finding. Subject: CN=DoD Root CA 3, OU=PKI, OU=DoD, O=U.S. Government, C=US Thumbprint: D73CA91102A2204A36459ED32213B467D7CE97FB NotAfter: 12/30/2029 Subject: CN=DoD Root CA 4, OU=PKI, OU=DoD, O=U.S. Government, C=US Thumbprint: B8269F25DBD937ECAFD4C35A9838571723F2D026 NotAfter: 7/25/2032 Subject: CN=DoD Root CA 5, OU=PKI, OU=DoD, O=U.S. Government, C=US Thumbprint: 4ECB5CC3095670454DA1CBD410FC921F46B8564B NotAfter: 6/14/2041 Subject: CN=DoD Root CA 6, OU=PKI, OU=DoD, O=U.S. Government, C=US Thumbprint: D37ECF61C0B4ED88681EF3630C4E2FC787B37AEF Valid to: Friday, January 24, 2053 Alternately, use the Certificates MMC snap-in: Run "MMC". Select "File", "Add/Remove Snap-in". Select "Certificates" and click "Add". Select "Computer account" and click "Next". Select "Local computer: (the computer this console is running on)" and click "Finish". Click "OK". Expand "Certificates" and navigate to "Trusted Root Certification Authorities >> Certificates". For each of the DoD Root CA certificates noted below: Right-click on the certificate and select "Open". Select the "Details" tab. Scroll to the bottom and select "Thumbprint". If the DoD Root CA certificates below are not listed or the value for the "Thumbprint" field is not as noted, this is a finding. DoD Root CA 3 Thumbprint: D73CA91102A2204A36459ED32213B467D7CE97FB Valid to: Sunday, December 30, 2029 DoD Root CA 4 Thumbprint: B8269F25DBD937ECAFD4C35A9838571723F2D026 Valid to: Sunday, July 25, 2032 DoD Root CA 5 Thumbprint: 4ECB5CC3095670454DA1CBD410FC921F46B8564B Valid to: Friday, June 14, 2041 DoD Root CA 6 Thumbprint: D37ECF61C0B4ED88681EF3630C4E2FC787B37AEF Valid to: Friday, January 24, 2053
Discussion
To ensure secure DoD websites and DoD-signed code are properly validated, the system must trust the DoD Root Certificate Authorities (CAs). The DoD root certificates will ensure that the trust chain is established for server certificates issued from the DoD CAs. Satisfies: SRG-OS-000066-GPOS-00034, SRG-OS-000403-GPOS-00182
Fix
Install the DoD Root CA certificates: DoD Root CA 3 DoD Root CA 4 DoD Root CA 5 DoD Root CA 6 The InstallRoot tool is available on Cyber Exchange at https://cyber.mil/pki-pke/tools-configuration-files. Certificate bundles published by the PKI can be found at https://crl.gds.disa.mil/.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000130: Windows Server 2016 must be configured to require a strong session key.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\Netlogon\Parameters\ Value Name: RequireStrongKey Value Type: REG_DWORD Value: 0x00000001 (1) This setting may prevent a system from being joined to a domain if not configured consistently between systems.
Discussion
A computer connecting to a domain controller will establish a secure channel. The secure channel connection may be subject to compromise, such as hijacking or eavesdropping, if strong session keys are not used to establish the connection. Requiring strong session keys enforces 128-bit encryption between systems. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Domain member: Require strong (Windows 2000 or Later) session key" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000270: Windows Server 2016 must be configured to audit Logon/Logoff - Logon failures.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Logon/Logoff >> Logon - Failure
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Logon records user logons. If this is an interactive logon, it is recorded on the local system. If it is to a network share, it is recorded on the system accessed. Satisfies: SRG-OS-000032-GPOS-00013, SRG-OS-000470-GPOS-00214, SRG-OS-000472-GPOS-00217, SRG-OS-000473-GPOS-00218, SRG-OS-000475-GPOS-00220
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Logon/Logoff >> "Audit Logon" with "Failure" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000300: The Application event log size must be configured to 32768 KB or greater.
If the system is configured to write events directly to an audit server, this is NA. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\EventLog\Application\ Value Name: MaxSize Type: REG_DWORD Value: 0x00008000 (32768) (or greater)
Discussion
Inadequate log size will cause the log to fill up quickly. This may prevent audit events from being recorded properly and require frequent attention by administrative personnel.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Event Log Service >> Application >> "Specify the maximum log file size (KB)" to "Enabled" with a "Maximum Log Size (KB)" of "32768" or greater.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000170: Permissions for program file directories must conform to minimum requirements.
The default permissions are adequate when the Security Option "Network access: Let everyone permissions apply to anonymous users" is set to "Disabled" (WN16-SO-000290). Review the permissions for the program file directories (Program Files and Program Files [x86]). Non-privileged groups such as Users or Authenticated Users must not have greater than "Read & execute" permissions. (Individual accounts must not be used to assign permissions.) If permissions are not as restrictive as the default permissions listed below, this is a finding. Viewing in File Explorer: For each folder, view the Properties. Select the "Security" tab, and the "Advanced" button. Default permissions: \Program Files and \Program Files (x86) Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to TrustedInstaller - Full control - This folder and subfolders SYSTEM - Modify - This folder only SYSTEM - Full control - Subfolders and files only Administrators - Modify - This folder only Administrators - Full control - Subfolders and files only Users - Read & execute - This folder, subfolders and files CREATOR OWNER - Full control - Subfolders and files only ALL APPLICATION PACKAGES - Read & execute - This folder, subfolders, and files ALL RESTRICTED APPLICATION PACKAGES - Read & execute - This folder, subfolders, and files Alternately, use icacls: Open a Command prompt (admin). Enter "icacls" followed by the directory: 'icacls "c:\program files"' 'icacls "c:\program files (x86)"' The following results should be displayed for each when entered: c:\program files (c:\program files (x86)) NT SERVICE\TrustedInstaller:(F) NT SERVICE\TrustedInstaller:(CI)(IO)(F) NT AUTHORITY\SYSTEM:(M) NT AUTHORITY\SYSTEM:(OI)(CI)(IO)(F) BUILTIN\Administrators:(M) BUILTIN\Administrators:(OI)(CI)(IO)(F) BUILTIN\Users:(RX) BUILTIN\Users:(OI)(CI)(IO)(GR,GE) CREATOR OWNER:(OI)(CI)(IO)(F) APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(RX) APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(OI)(CI)(IO)(GR,GE) APPLICATION PACKAGE AUTHORITY\ALL RESTRICTED APPLICATION PACKAGES:(RX) APPLICATION PACKAGE AUTHORITY\ALL RESTRICTED APPLICATION PACKAGES:(OI)(CI)(IO)(GR,GE) Successfully processed 1 files; Failed processing 0 files
Discussion
Changing the system's file and directory permissions allows the possibility of unauthorized and anonymous modification to the operating system and installed applications. The default permissions are adequate when the Security Option "Network access: Let everyone permissions apply to anonymous users" is set to "Disabled" (WN16-SO-000290). Satisfies: SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000312-GPOS-00124
Fix
Maintain the default permissions for the program file directories and configure the Security Option "Network access: Let everyone permissions apply to anonymous users" to "Disabled" (WN16-SO-000290). Default permissions: \Program Files and \Program Files (x86) Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to TrustedInstaller - Full control - This folder and subfolders SYSTEM - Modify - This folder only SYSTEM - Full control - Subfolders and files only Administrators - Modify - This folder only Administrators - Full control - Subfolders and files only Users - Read & execute - This folder, subfolders, and files CREATOR OWNER - Full control - Subfolders and files only ALL APPLICATION PACKAGES - Read & execute - This folder, subfolders, and files ALL RESTRICTED APPLICATION PACKAGES - Read & execute - This folder, subfolders, and files
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000320: Windows Server 2016 must employ automated mechanisms to determine the state of system components with regard to flaw remediation using the following frequency: continuously, where Endpoint Security Solution (ESS) is used; 30 days, for any additional internal network scans not covered by ESS; and annually, for external scans by Computer Network Defense Service Provider (CNDSP).
Verify DoD-approved ESS software is installed and properly operating. Ask the site ISSM for documentation of the ESS software installation and configuration. If the ISSM is not able to provide a documented configuration for an installed ESS or if the ESS software is not properly maintained or used, this is a finding. Note: Example of documentation can be a copy of the site's CCB approved Software Baseline with version of software noted or a memo from the ISSM stating current ESS software and version.
Discussion
Without the use of automated mechanisms to scan for security flaws on a continuous and/or periodic basis, the operating system or other system components may remain vulnerable to the exploits presented by undetected software flaws. The operating system may have an integrated solution incorporating continuous scanning using ESS and periodic scanning using other tools.
Fix
Install a DoD-approved ESS software and ensure it is operating continuously.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
Old Rule ID 'SV-224847r569186_rule'
WN16-00-000190: Default permissions for the HKEY_LOCAL_MACHINE registry hive must be maintained.
Review the registry permissions for the keys of the HKEY_LOCAL_MACHINE hive noted below. If any non-privileged groups such as Everyone, Users, or Authenticated Users have greater than Read permission, this is a finding. If permissions are not as restrictive as the default permissions listed below, this is a finding. Run "Regedit". Right-click on the registry areas noted below. Select "Permissions..." and the "Advanced" button. HKEY_LOCAL_MACHINE\SECURITY Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to SYSTEM - Full Control - This key and subkeys Administrators - Special - This key and subkeys HKEY_LOCAL_MACHINE\SOFTWARE Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to Users - Read - This key and subkeys Administrators - Full Control - This key and subkeys SYSTEM - Full Control - This key and subkeys CREATOR OWNER - Full Control - This key and subkeys ALL APPLICATION PACKAGES - Read - This key and subkeys HKEY_LOCAL_MACHINE\SYSTEM Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to Users - Read - This key and subkeys Administrators - Full Control - This key and subkeys SYSTEM - Full Control - This key and subkeys CREATOR OWNER - Full Control - Subkeys only ALL APPLICATION PACKAGES - Read - This key and subkeys Server Operators – Read – This Key and subkeys (Domain controllers only) Other examples under the noted keys may also be sampled. There may be some instances where non-privileged groups have greater than Read permission. If the defaults have not been changed, these are not a finding.
Discussion
The registry is integral to the function, security, and stability of the Windows system. Changing the system's registry permissions allows the possibility of unauthorized and anonymous modification to the operating system.
Fix
Maintain the default permissions for the HKEY_LOCAL_MACHINE registry hive. The default permissions of the higher-level keys are noted below. HKEY_LOCAL_MACHINE\SECURITY Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to SYSTEM - Full Control - This key and subkeys Administrators - Special - This key and subkeys HKEY_LOCAL_MACHINE\SOFTWARE Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to Users - Read - This key and subkeys Administrators - Full Control - This key and subkeys SYSTEM - Full Control - This key and subkeys CREATOR OWNER - Full Control - This key and subkeys ALL APPLICATION PACKAGES - Read - This key and subkeys HKEY_LOCAL_MACHINE\SYSTEM Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to Users - Read - This key and subkeys Administrators - Full Control - This key and subkeys SYSTEM - Full Control - This key and subkeys CREATOR OWNER - Full Control - Subkeys only ALL APPLICATION PACKAGES - Read - This key and subkeys Server Operators – Read – This Key and subkeys (Domain controllers only)
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000090: Hardened UNC paths must be defined to require mutual authentication and integrity for at least the \\*\SYSVOL and \\*\NETLOGON shares.
This requirement is applicable to domain-joined systems. For standalone or nondomain-joined systems, this is NA. If the following registry values do not exist or are not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\NetworkProvider\HardenedPaths\ Value Name: \\*\NETLOGON Value Type: REG_SZ Value: RequireMutualAuthentication=1, RequireIntegrity=1 Value Name: \\*\SYSVOL Value Type: REG_SZ Value: RequireMutualAuthentication=1, RequireIntegrity=1 Additional entries would not be a finding.
Discussion
Additional security requirements are applied to Universal Naming Convention (UNC) paths specified in hardened UNC paths before allowing access to them. This aids in preventing tampering with or spoofing of connections to these paths.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Network >> Network Provider >> "Hardened UNC Paths" to "Enabled" with at least the following configured in "Hardened UNC Paths": (click the "Show" button to display) Value Name: \\*\SYSVOL Value: RequireMutualAuthentication=1, RequireIntegrity=1 Value Name: \\*\NETLOGON Value: RequireMutualAuthentication=1, RequireIntegrity=1
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000010: The display of slide shows on the lock screen must be disabled.
Verify the registry value below. If it does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\Personalization\ Value Name: NoLockScreenSlideshow Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Slide shows that are displayed on the lock screen could display sensitive information to unauthorized personnel. Turning off this feature will limit access to the information to a logged-on user.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Control Panel >> Personalization >> "Prevent enabling lock screen slide show" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000480: Windows 2016 systems must have Unified Extensible Firmware Interface (UEFI) firmware and be configured to run in UEFI mode, not Legacy BIOS.
Some older systems may not have UEFI firmware. This is currently a CAT III; it will be raised in severity at a future date when broad support of Windows hardware and firmware requirements are expected to be met. Devices that have UEFI firmware must run in "UEFI" mode. Verify the system firmware is configured to run in "UEFI" mode, not "Legacy BIOS". Run "System Information". Under "System Summary", if "BIOS Mode" does not display "UEFI", this is a finding.
Discussion
UEFI provides additional security features in comparison to legacy BIOS firmware, including Secure Boot. UEFI is required to support additional security features in Windows Server 2016, including Virtualization Based Security and Credential Guard. Systems with UEFI that are operating in "Legacy BIOS" mode will not support these security features.
Fix
Configure UEFI firmware to run in "UEFI" mode, not "Legacy BIOS" mode.
Rating Info
DISA Cat III. NIST impact 2.
Expert Comment
None
WN16-SO-000010: Windows Server 2016 built-in guest account must be disabled.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options. If the value for "Accounts: Guest account status" is not set to "Disabled", this is a finding. For server core installations, run the following command: Secedit /Export /Areas SecurityPolicy /CFG C:\Path\FileName.Txt If "EnableGuestAccount" equals "1" in the file, this is a finding.
Discussion
A system faces an increased vulnerability threat if the built-in guest account is not disabled. This is a known account that exists on all Windows systems and cannot be deleted. This account is initialized during the installation of the operating system with no password assigned.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Accounts: Guest account status" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000430: Basic authentication for RSS feeds over HTTP must not be used.
The default behavior is for the Windows RSS platform to not use Basic authentication over HTTP connections. If the registry value name below does not exist, this is not a finding. If it exists and is configured with a value of "0", this is not a finding. If it exists and is configured with a value of "1", this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Internet Explorer\Feeds\ Value Name: AllowBasicAuthInClear Value Type: REG_DWORD Value: 0x00000000 (0) (or if the Value Name does not exist)
Discussion
Basic authentication uses plain-text passwords that could be used to compromise a system. Disabling Basic authentication will reduce this potential.
Fix
The default behavior is for the Windows RSS platform to not use Basic authentication over HTTP connections. If this needs to be corrected, configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> RSS Feeds >> "Turn on Basic feed authentication over HTTP" to "Not Configured" or "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000070: The Back up files and directories user right must only be assigned to the Administrators group.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Back up files and directories" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeBackupPrivilege" user right, this is a finding. S-1-5-32-544 (Administrators) If an application requires this user right, this would not be a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070).
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Back up files and directories" user right can circumvent file and directory permissions and could allow access to sensitive data.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Back up files and directories" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000340: The Access this computer from the network user right must only be assigned to the Administrators, Authenticated Users, and Enterprise Domain Controllers groups on domain controllers.
This applies to domain controllers. It is NA for other systems. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Access this computer from the network" right, this is a finding. - Administrators - Authenticated Users - Enterprise Domain Controllers For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeNetworkLogonRight" user right, this is a finding. S-1-5-32-544 (Administrators) S-1-5-11 (Authenticated Users) S-1-5-9 (Enterprise Domain Controllers) If an application requires this user right, this would not be a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070).
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Access this computer from the network" right may access resources on the system, and this right must be limited to those requiring it.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Access this computer from the network" to include only the following accounts or groups: - Administrators - Authenticated Users - Enterprise Domain Controllers
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000160: Permissions for the system drive root directory (usually C:\) must conform to minimum requirements.
The default permissions are adequate when the Security Option "Network access: Let everyone permissions apply to anonymous users" is set to "Disabled" (WN16-SO-000290). Review the permissions for the system drive's root directory (usually C:\). Non-privileged groups such as Users or Authenticated Users must not have greater than "Read & execute" permissions except where noted as defaults. (Individual accounts must not be used to assign permissions.) If permissions are not as restrictive as the default permissions listed below, this is a finding. Viewing in File Explorer: View the Properties of the system drive's root directory. Select the "Security" tab, and the "Advanced" button. Default permissions: C:\ Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to SYSTEM - Full control - This folder, subfolders, and files Administrators - Full control - This folder, subfolders, and files Users - Read & execute - This folder, subfolders, and files Users - Create folders/append data - This folder and subfolders Users - Create files/write data - Subfolders only CREATOR OWNER - Full Control - Subfolders and files only Alternately, use icacls: Open "Command Prompt (Admin)". Enter "icacls" followed by the directory: "icacls c:\" The following results should be displayed: c:\ NT AUTHORITY\SYSTEM:(OI)(CI)(F) BUILTIN\Administrators:(OI)(CI)(F) BUILTIN\Users:(OI)(CI)(RX) BUILTIN\Users:(CI)(AD) BUILTIN\Users:(CI)(IO)(WD) CREATOR OWNER:(OI)(CI)(IO)(F) Successfully processed 1 files; Failed processing 0 files
Discussion
Changing the system's file and directory permissions allows the possibility of unauthorized and anonymous modification to the operating system and installed applications. The default permissions are adequate when the Security Option "Network access: Let everyone permissions apply to anonymous users" is set to "Disabled" (WN16-SO-000290). Satisfies: SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000312-GPOS-00124
Fix
Maintain the default permissions for the system drive's root directory and configure the Security Option "Network access: Let everyone permissions apply to anonymous users" to "Disabled" (WN16-SO-000290). Default Permissions C:\ Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to SYSTEM - Full control - This folder, subfolders, and files Administrators - Full control - This folder, subfolders, and files Users - Read & execute - This folder, subfolders, and files Users - Create folders/append data - This folder and subfolders Users - Create files/write data - Subfolders only CREATOR OWNER - Full Control - Subfolders and files only
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000520: The Windows Remote Management (WinRM) client must not use Digest authentication.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\WinRM\Client\ Value Name: AllowDigest Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Digest authentication is not as strong as other options and may be subject to man-in-the-middle attacks. Disallowing Digest authentication will reduce this potential.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Windows Remote Management (WinRM) >> WinRM Client >> "Disallow Digest authentication" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-PK-000030: The US DoD CCEB Interoperability Root CA cross-certificates must be installed in the Untrusted Certificates Store on unclassified systems.
Verify the US DoD CCEB Interoperability Root CA cross-certificate is installed on unclassified systems as an Untrusted Certificate. Run "PowerShell" as an administrator. Execute the following command: Get-ChildItem -Path Cert:Localmachine\disallowed | Where Issuer -Like "*CCEB Interoperability*" | FL Subject, Issuer, Thumbprint, NotAfter If the following certificate "Subject", "Issuer", and "Thumbprint" information is not displayed, this is a finding. Subject: CN=DoD Root CA 3, OU=PKI, OU=DoD, O=U.S. Government, C=US Issuer: CN=US DoD CCEB Interoperability Root CA 2, OU=PKI, OU=DoD, O=U.S. Government, C=US Thumbprint: 9B74964506C7ED9138070D08D5F8B969866560C8 NotAfter: 7/18/2025 Alternately use the Certificates MMC snap-in: Run "MMC". Select "File", "Add/Remove Snap-in". Select "Certificates", click "Add". Select "Computer account", click "Next". Select "Local computer: (the computer this console is running on)", click "Finish". Click "OK". Expand "Certificates" and navigate to "Untrusted Certificates >> Certificates". For each certificate with "US DoD CCEB Interoperability Root CA …" under "Issued By": Right-click on the certificate and select "Open". Select the "Details" tab. Scroll to the bottom and select "Thumbprint". If the certificate below is not listed or the value for the "Thumbprint" field is not as noted, this is a finding. Subject: CN=DoD Root CA 3, OU=PKI, OU=DoD, O=U.S. Government, C=US Issuer: CN=US DoD CCEB Interoperability Root CA 2, OU=PKI, OU=DoD, O=U.S. Government, C=US Thumbprint: 9B74964506C7ED9138070D08D5F8B969866560C8 NotAfter: 7/18/2025
Discussion
To ensure users do not experience denial of service when performing certificate-based authentication to DoD websites due to the system chaining to a root other than DoD Root CAs, the US DoD CCEB Interoperability Root CA cross-certificates must be installed in the Untrusted Certificate Store. This requirement only applies to unclassified systems. Satisfies: SRG-OS-000066-GPOS-00034, SRG-OS-000403-GPOS-00182
Fix
Install the US DoD CCEB Interoperability Root CA cross-certificate on unclassified systems. Subject: CN=DoD Root CA 3, OU=PKI, OU=DoD, O=U.S. Government, C=US Issuer: CN=US DoD CCEB Interoperability Root CA 2, OU=PKI, OU=DoD, O=U.S. Government, C=US Thumbprint: 9B74964506C7ED9138070D08D5F8B969866560C8 NotAfter: 7/18/2025 The certificates can be installed using the InstallRoot tool. The tool and user guide are available on Cyber Exchange at https://cyber.mil/pki-pke/tools-configuration-files. Certificate bundles published by the PKI can be found at https://crl.gds.disa.mil/.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000330: NTLM must be prevented from falling back to a Null session.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\LSA\MSV1_0\ Value Name: allownullsessionfallback Type: REG_DWORD Value: 0x00000000 (0)
Discussion
NTLM sessions that are allowed to fall back to Null (unauthenticated) sessions may gain unauthorized access.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network security: Allow LocalSystem NULL session fallback" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000240: The Load and unload device drivers user right must only be assigned to the Administrators group.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Load and unload device drivers" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeLoadDriverPrivilege" user right, this is a finding. S-1-5-32-544 (Administrators)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Load and unload device drivers" user right allows a user to load device drivers dynamically on a system. This could be used by an attacker to install malicious code.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Load and unload device drivers" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AC-000090: Windows Server 2016 reversible password encryption must be disabled.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Password Policy. If the value for "Store passwords using reversible encryption" is not set to "Disabled", this is a finding. For server core installations, run the following command: Secedit /Export /Areas SecurityPolicy /CFG C:\Path\FileName.Txt If "ClearTextPassword" equals "1" in the file, this is a finding.
Discussion
Storing passwords using reversible encryption is essentially the same as storing clear-text versions of the passwords, which are easily compromised. For this reason, this policy must never be enabled.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Password Policy >> "Store passwords using reversible encryption" to "Disabled".
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-CC-000050: Source routing must be configured to the highest protection level to prevent Internet Protocol (IP) source routing.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\ Value Name: DisableIPSourceRouting Value Type: REG_DWORD Value: 0x00000002 (2)
Discussion
Configuring the system to disable IP source routing protects against spoofing.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> MSS (Legacy) >> "MSS: (DisableIPSourceRouting) IP source routing protection level (protects against packet spoofing)" to "Enabled" with "Highest protection, source routing is completely disabled" selected. This policy setting requires the installation of the MSS-Legacy custom templates included with the STIG package. "MSS-Legacy.admx" and "MSS-Legacy.adml" must be copied to the \Windows\PolicyDefinitions and \Windows\PolicyDefinitions\en-US directories respectively.
Rating Info
DISA Cat III. NIST impact 2.
Expert Comment
None
WN16-DC-000310: Active Directory user accounts, including administrators, must be configured to require the use of a Common Access Card (CAC), Personal Identity Verification (PIV)-compliant hardware token, or Alternate Logon Token (ALT) for user authentication.
This applies to domain controllers. It is NA for other systems. Open "PowerShell". Enter the following: "Get-ADUser -Filter {(Enabled -eq $True) -and (SmartcardLogonRequired -eq $False)} | FT Name" ("DistinguishedName" may be substituted for "Name" for more detailed output.) If any user accounts, including administrators, are listed, this is a finding. Alternately: To view sample accounts in "Active Directory Users and Computers" (available from various menus or run "dsa.msc"): Select the Organizational Unit (OU) where the user accounts are located. (By default, this is the Users node; however, accounts may be under other organization-defined OUs.) Right-click the sample user account and select "Properties". Select the "Account" tab. If any user accounts, including administrators, do not have "Smart card is required for interactive logon" checked in the "Account Options" area, this is a finding.
Discussion
Smart cards such as the CAC support a two-factor authentication technique. This provides a higher level of trust in the asserted identity than use of the username and password for authentication. Satisfies: SRG-OS-000105-GPOS-00052, SRG-OS-000106-GPOS-00053, SRG-OS-000107-GPOS-00054, SRG-OS-000108-GPOS-00055, SRG-OS-000375-GPOS-00160
Fix
Configure all user accounts, including administrator accounts, in Active Directory to enable the option "Smart card is required for interactive logon". Run "Active Directory Users and Computers" (available from various menus or run "dsa.msc"): Select the OU where the user accounts are located. (By default this is the Users node; however, accounts may be under other organization-defined OUs.) Right-click the user account and select "Properties". Select the "Account" tab. Check "Smart card is required for interactive logon" in the "Account Options" area.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000160: Downloading print driver packages over HTTP must be prevented.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows NT\Printers\ Value Name: DisableWebPnPDownload Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Some features may communicate with the vendor, sending system information or downloading data or components for the feature. Turning off this capability will prevent potentially sensitive information from being sent outside the enterprise and will prevent uncontrolled updates to the system. This setting prevents the computer from downloading print driver packages over HTTP.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> System >> Internet Communication Management >> Internet Communication settings >> "Turn off downloading of print drivers over HTTP" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000040: The Kerberos user ticket lifetime must be limited to 10 hours or less.
This applies to domain controllers. It is NA for other systems. Verify the following is configured in the Default Domain Policy. Open "Group Policy Management". Navigate to "Group Policy Objects" in the Domain being reviewed (Forest >> Domains >> Domain). Right-click on the "Default Domain Policy". Select "Edit". Navigate to Computer Configuration >> Policies >> Windows Settings >> Security Settings >> Account Policies >> Kerberos Policy. If the value for "Maximum lifetime for user ticket" is "0" or greater than "10" hours, this is a finding.
Discussion
In Kerberos, there are two types of tickets: Ticket Granting Tickets (TGTs) and Service Tickets. Kerberos tickets have a limited lifetime so the time an attacker has to implement an attack is limited. This policy controls how long TGTs can be renewed. With Kerberos, the user's initial authentication to the domain controller results in a TGT, which is then used to request Service Tickets to resources. Upon startup, each computer gets a TGT before requesting a service ticket to the domain controller and any other computers it needs to access. For services that start up under a specified user account, users must always get a TGT first and then get Service Tickets to all computers and services accessed. Satisfies: SRG-OS-000112-GPOS-00057, SRG-OS-000113-GPOS-00058
Fix
Configure the policy value in the Default Domain Policy for Computer Configuration >> Policies >> Windows Settings >> Security Settings >> Account Policies >> Kerberos Policy >> "Maximum lifetime for user ticket" to a maximum of "10" hours but not "0", which equates to "Ticket doesn't expire".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000260: Windows Server 2016 must be configured to audit Logon/Logoff - Logon successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Logon/Logoff >> Logon - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Logon records user logons. If this is an interactive logon, it is recorded on the local system. If it is to a network share, it is recorded on the system accessed. Satisfies: SRG-OS-000032-GPOS-00013, SRG-OS-000470-GPOS-00214, SRG-OS-000472-GPOS-00217, SRG-OS-000473-GPOS-00218, SRG-OS-000475-GPOS-00220
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Logon/Logoff >> "Audit Logon" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000170: Windows Server 2016 must be configured to audit Detailed Tracking - Process Creation successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Detailed Tracking >> Process Creation - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Process Creation records events related to the creation of a process and the source. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000471-GPOS-00215
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Detailed Tracking >> "Audit Process Creation" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000430: The password for the krbtgt account on a domain must be reset at least every 180 days.
This requirement is applicable to domain controllers; it is NA for other systems. Open "Windows PowerShell". Enter "Get-ADUser krbtgt -Property PasswordLastSet". If the "PasswordLastSet" date is more than 180 days old, this is a finding.
Discussion
The krbtgt account acts as a service account for the Kerberos Key Distribution Center (KDC) service. The account and password are created when a domain is created and the password is typically not changed. If the krbtgt account is compromised, attackers can create valid Kerberos Ticket Granting Tickets (TGT). The password must be changed twice to effectively remove the password history.Changing once, waiting for replication to complete and the amount of time equal to or greater than the maximum Kerberos ticket lifetime, and changing again reduces the risk of issues.
Fix
Reset the password for the krbtgt account a least every 180 days. The password must be changed twice to effectively remove the password history. Changing once, waiting for replication to complete and changing again reduces the risk of issues. Changing twice in rapid succession forces clients to re-authenticate (including application services) but is desired if a compromise is suspected. PowerShell scripts are available to accomplish this such as at the following link: https://gallery.technet.microsoft.com/Reset-the-krbtgt-account-581a9e51 Open "Active Directory Users and Computers" (available from various menus or run "dsa.msc"). Select "Advanced Features" in the "View" menu if not previously selected. Select the "Users" node. Right click on the krbtgt account and select "Reset password". Enter a password that meets password complexity requirements. Clear the "User must change password at next logon" check box. The system will automatically change this to a system generated complex password.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000470: UIAccess applications must not be allowed to prompt for elevation without using the secure desktop.
UAC requirements are NA for Server Core installations (this is the default installation option for Windows Server 2016 versus Server with Desktop Experience) as well as Nano Server. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ Value Name: EnableUIADesktopToggle Value Type: REG_DWORD Value: 0x00000000 (0)
Discussion
User Account Control (UAC) is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting prevents User Interface Accessibility programs from disabling the secure desktop for elevation prompts.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "User Account Control: Allow UIAccess applications to prompt for elevation without using the secure desktop" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000210: The Active Directory AdminSDHolder object must be configured with proper audit settings.
This applies to domain controllers. It is NA for other systems. Review the auditing configuration for the "AdminSDHolder" object. Open "Active Directory Users and Computers" (available from various menus or run "dsa.msc"). Ensure "Advanced Features" is selected in the "View" menu. Select "System" under the domain being reviewed in the left pane. Right-click the "AdminSDHolder" object in the right pane and select "Properties". Select the "Security" tab. Select the "Advanced" button and then the "Auditing" tab. If the audit settings on the "AdminSDHolder" object are not at least as inclusive as those below, this is a finding. Type - Fail Principal - Everyone Access - Full Control Inherited from - None Applies to - This object only The success types listed below are defaults. Where Special is listed in the summary screens for Access, detailed Permissions are provided for reference. Various Properties selections may also exist by default. Type - Success Principal - Everyone Access - Special Inherited from - None Applies to - This object only (Access - Special = Write all properties, Modify permissions, Modify owner) Two instances with the following summary information will be listed. Type - Success Principal - Everyone Access - (blank) Inherited from - (CN of domain) Applies to - Descendant Organizational Unit objects
Discussion
When inappropriate audit settings are configured for directory service database objects, it may be possible for a user or process to update the data without generating any tracking data. The impact of missing audit data is related to the type of object. A failure to capture audit data for objects used by identification, authentication, or authorization functions could degrade or eliminate the ability to track changes to access policy for systems or data. For Active Directory (AD), there are a number of critical object types in the domain naming context of the AD database for which auditing is essential. This includes the AdminSDHolder object. Because changes to these objects can significantly impact access controls or the availability of systems, the absence of auditing data makes it impossible to identify the source of changes that impact the confidentiality, integrity, and availability of data and systems throughout an AD domain. The lack of proper auditing can result in insufficient forensic evidence needed to investigate an incident and prosecute the intruder. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Open "Active Directory Users and Computers" (available from various menus or run "dsa.msc"). Ensure "Advanced Features" is selected in the "View" menu. Select "System" under the domain being reviewed in the left pane. Right-click the "AdminSDHolder" object in the right pane and select "Properties". Select the "Security" tab. Select the "Advanced" button and then the "Auditing" tab. Configure the audit settings for AdminSDHolder object to include the following. Type - Fail Principal - Everyone Access - Full Control Inherited from - None Applies to - This object only The success types listed below are defaults. Where Special is listed in the summary screens for Access, detailed Permissions are provided for reference. Various Properties selections may also exist by default. Type - Success Principal - Everyone Access - Special Inherited from - None Applies to - This object only (Access - Special = Write all properties, Modify permissions, Modify owner) Two instances with the following summary information will be listed. Type - Success Principal - Everyone Access - (blank) Inherited from - (CN of domain) Applies to - Descendant Organizational Unit objects
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000250: Windows Server 2016 must be configured to audit DS Access - Directory Service Access failures.
This applies to domain controllers. It is NA for other systems. Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. DS Access >> Directory Service Access - Failure
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Audit Directory Service Access records events related to users accessing an Active Directory object. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> DS Access >> "Directory Service Access" with "Failure" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000460: Orphaned security identifiers (SIDs) must be removed from user rights on Windows 2016.
Review the effective User Rights setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. Review each User Right listed for any unresolved SIDs to determine whether they are valid, such as due to being temporarily disconnected from the domain. (Unresolved SIDs have the format of "*S-1-…".) If any unresolved SIDs exist and are not for currently valid accounts or groups, this is a finding. For server core installations, run the following command: Secedit /export /areas USER_RIGHTS /cfg c:\path\UserRights.txt The results in the file identify user right assignments by SID instead of group name. Review the SIDs for unidentified ones. A list of typical SIDs \ Groups is below, search Microsoft for articles on well-known SIDs for others. If any unresolved SIDs exist and are not for currently valid accounts or groups, this is a finding. SID - Group S-1-5-11 - Authenticated Users S-1-5-113 - Local account S-1-5-114 - Local account and member of Administrators group S-1-5-19 - Local Service S-1-5-20 - Network Service S-1-5-32-544 - Administrators S-1-5-32-546 - Guests S-1-5-6 - Service S-1-5-9 - Enterprise Domain Controllers S-1-5-domain-512 - Domain Admins S-1-5-root domain-519 - Enterprise Admins S-1-5-80-3139157870-2983391045-3678747466-658725712-1809340420 - NT Service\WdiServiceHost
Discussion
Accounts or groups given rights on a system may show up as unresolved SIDs for various reasons including deletion of the accounts or groups. If the account or group objects are reanimated, there is a potential they may still have rights no longer intended. Valid domain accounts or groups may also show up as unresolved SIDs if a connection to the domain cannot be established for some reason.
Fix
Remove any unresolved SIDs found in User Rights assignments and determined to not be for currently valid accounts or groups by removing the accounts or groups from the appropriate group policy.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000380: Windows Server 2016 must be configured to audit System - IPsec Driver failures.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. System >> IPsec Driver - Failure
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. IPsec Driver records events related to the IPsec Driver, such as dropped packets. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> System >> "Audit IPsec Driver" with "Failure" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000510: The Windows Remote Management (WinRM) client must not allow unencrypted traffic.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\WinRM\Client\ Value Name: AllowUnencryptedTraffic Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Unencrypted remote access to a system can allow sensitive information to be compromised. Windows remote management connections must be encrypted to prevent this. Satisfies: SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Windows Remote Management (WinRM) >> WinRM Client >> "Allow unencrypted traffic" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000250: Non-system-created file shares on a system must limit access to groups that require it.
If only system-created shares such as "ADMIN$", "C$", and "IPC$" exist on the system, this is NA. (System-created shares will display a message that it has been shared for administrative purposes when "Properties" is selected.) Run "Computer Management". Navigate to System Tools >> Shared Folders >> Shares. Right-click any non-system-created shares. Select "Properties". Select the "Share Permissions" tab. If the file shares have not been configured to restrict permissions to the specific groups or accounts that require access, this is a finding. Select the "Security" tab. If the permissions have not been configured to restrict permissions to the specific groups or accounts that require access, this is a finding.
Discussion
Shares on a system provide network access. To prevent exposing sensitive information, where shares are necessary, permissions must be reconfigured to give the minimum access to accounts that require it.
Fix
If a non-system-created share is required on a system, configure the share and NTFS permissions to limit access to the specific groups or accounts that require it. Remove any unnecessary non-system-created shares.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000160: The directory service must be configured to terminate LDAP-based network connections to the directory server after 5 minutes of inactivity.
This applies to domain controllers. It is NA for other systems. Open an elevated "Command Prompt" (run as administrator). Enter "ntdsutil". At the "ntdsutil:" prompt, enter "LDAP policies". At the "ldap policy:" prompt, enter "connections". At the "server connections:" prompt, enter "connect to server [host-name]" (where [host-name] is the computer name of the domain controller). At the "server connections:" prompt, enter "q". At the "ldap policy:" prompt, enter "show values". If the value for MaxConnIdleTime is greater than "300" (5 minutes) or is not specified, this is a finding. Enter "q" at the "ldap policy:" and "ntdsutil:" prompts to exit. Alternately, Dsquery can be used to display MaxConnIdleTime: Open "Command Prompt (Admin)". Enter the following command (on a single line). dsquery * "cn=Default Query Policy,cn=Query-Policies,cn=Directory Service, cn=Windows NT,cn=Services,cn=Configuration,dc=[forest-name]" -attr LDAPAdminLimits The quotes are required and dc=[forest-name] is the fully qualified LDAP name of the domain being reviewed (e.g., dc=disaost,dc=mil). If the results do not specify a "MaxConnIdleTime" or it has a value greater than "300" (5 minutes), this is a finding.
Discussion
The failure to terminate inactive network connections increases the risk of a successful attack on the directory server. The longer an established session is in progress, the more time an attacker has to hijack the session, implement a means to passively intercept data, or compromise any protections on client access. For example, if an attacker gains control of a client computer, an existing (already authenticated) session with the directory server could allow access to the directory. The lack of confidentiality protection in LDAP-based sessions increases exposure to this vulnerability.
Fix
Configure the directory service to terminate LDAP-based network connections to the directory server after 5 minutes of inactivity. Open an elevated "Command prompt" (run as administrator). Enter "ntdsutil". At the "ntdsutil:" prompt, enter "LDAP policies". At the "ldap policy:" prompt, enter "connections". At the "server connections:" prompt, enter "connect to server [host-name]" (where [host-name] is the computer name of the domain controller). At the "server connections:" prompt, enter "q". At the "ldap policy:" prompt, enter "Set MaxConnIdleTime to 300". Enter "Commit Changes" to save. Enter "Show values" to verify changes. Enter "q" at the "ldap policy:" and "ntdsutil:" prompts to exit.
Rating Info
DISA Cat III. NIST impact 2.
Expert Comment
None
WN16-AU-000310: Windows Server 2016 must be configured to audit Policy Change - Audit Policy Change successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Policy Change >> Audit Policy Change - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Audit Policy Change records events related to changes in audit policy. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Policy Change >> "Audit Audit Policy Change" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000110: The computer account password must not be prevented from being reset.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\Netlogon\Parameters\ Value Name: DisablePasswordChange Value Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Computer account passwords are changed automatically on a regular basis. Disabling automatic password changes can make the system more vulnerable to malicious access. Frequent password changes can be a significant safeguard for the system. A new password for the computer account will be generated every 30 days.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Domain member: Disable machine account password changes" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000290: Windows Server 2016 must be configured to audit Object Access - Removable Storage successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Object Access >> Removable Storage - Success Virtual machines or systems that use network attached storage may generate excessive audit events for secondary virtual drives or the network attached storage when this setting is enabled. This may be set to Not Configured in such cases and would not be a finding.
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Removable Storage auditing under Object Access records events related to access attempts on file system objects on removable storage devices.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Object Access >> "Audit Removable Storage" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000020: Kerberos user logon restrictions must be enforced.
This applies to domain controllers. It is NA for other systems. Verify the following is configured in the Default Domain Policy. Open "Group Policy Management". Navigate to "Group Policy Objects" in the Domain being reviewed (Forest >> Domains >> Domain). Right-click on the "Default Domain Policy". Select "Edit". Navigate to Computer Configuration >> Policies >> Windows Settings >> Security Settings >> Account Policies >> Kerberos Policy. If the "Enforce user logon restrictions" is not set to "Enabled", this is a finding.
Discussion
This policy setting determines whether the Kerberos Key Distribution Center (KDC) validates every request for a session ticket against the user rights policy of the target computer. The policy is enabled by default, which is the most secure setting for validating that access to target resources is not circumvented. Satisfies: SRG-OS-000112-GPOS-00057, SRG-OS-000113-GPOS-00058
Fix
Configure the policy value in the Default Domain Policy for Computer Configuration >> Policies >> Windows Settings >> Security Settings >> Account Policies >> Kerberos Policy >> "Enforce user logon restrictions" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000270: Anonymous enumeration of shares must not be allowed.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\Lsa\ Value Name: RestrictAnonymous Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Allowing anonymous logon users (null session connections) to list all account names and enumerate all shared resources can provide a map of potential points to attack the system.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network access: Do not allow anonymous enumeration of SAM accounts and shares" to "Enabled".
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-00-000440: FTP servers must be configured to prevent access to the system drive.
If FTP is not installed on the system, this is NA. Open "Internet Information Services (IIS) Manager". Select "Sites" under the server name. For any sites with a Binding that lists FTP, right-click the site and select "Explore". If the site is not defined to a specific folder for shared FTP resources, this is a finding. If the site includes any system areas such as root of the drive, Program Files, or Windows directories, this is a finding.
Discussion
The FTP service allows remote users to access shared files and directories that could provide access to system resources and compromise the system, especially if the user can gain access to the root directory of the boot drive.
Fix
Configure the FTP sites to allow access only to specific FTP shared resources. Do not allow access to other areas of the system.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000300: PKI certificates associated with user accounts must be issued by the DoD PKI or an approved External Certificate Authority (ECA).
This applies to domain controllers. It is NA for other systems. Review user account mappings to PKI certificates. Open "Windows PowerShell". Enter "Get-ADUser -Filter * | FT Name, UserPrincipalName, Enabled". Exclude disabled accounts (e.g., DefaultAccount, Guest) and the krbtgt account. If the User Principal Name (UPN) is not in the format of an individual's identifier for the certificate type and for the appropriate domain suffix, this is a finding. For standard NIPRNet certificates the individual's identifier is in the format of an Electronic Data Interchange - Personnel Identifier (EDI-PI). Alt Tokens and other certificates may use a different UPN format than the EDI-PI which vary by organization. Verified these with the organization. NIPRNet Example: Name - User Principal Name User1 - 1234567890@mil See PKE documentation for other network domain suffixes. If the mappings are to certificates issued by a CA authorized by the Component's CIO, this is a CAT II finding.
Discussion
A PKI implementation depends on the practices established by the Certificate Authority (CA) to ensure the implementation is secure. Without proper practices, the certificates issued by a CA have limited value in authentication functions.
Fix
Map user accounts to PKI certificates using the appropriate User Principal Name (UPN) for the network. See PKE documentation for details.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-00-000010: Users with Administrative privileges must have separate accounts for administrative duties and normal operational tasks.
Verify each user with administrative privileges has been assigned a unique administrative account separate from their standard user account. If users with administrative privileges do not have separate accounts for administrative functions and standard user functions, this is a finding.
Discussion
Using a privileged account to perform routine functions makes the computer vulnerable to malicious software inadvertently introduced during a session that has been granted full privileges.
Fix
Ensure each user with administrative privileges has a separate account for user duties and one for privileged duties.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-00-000380: Simple TCP/IP Services must not be installed.
Open "PowerShell". Enter "Get-WindowsFeature | Where Name -eq Simple-TCPIP". If "Installed State" is "Installed", this is a finding. An Installed State of "Available" or "Removed" is not a finding.
Discussion
Unnecessary services increase the attack surface of a system. Some of these services may not support required levels of authentication or encryption or may provide unauthorized access to the system.
Fix
Uninstall the "Simple TCP/IP Services" feature. Start "Server Manager". Select the server with the feature. Scroll down to "ROLES AND FEATURES" in the right pane. Select "Remove Roles and Features" from the drop-down "TASKS" list. Select the appropriate server on the "Server Selection" page and click "Next". Deselect "Simple TCP/IP Services" on the "Features" page. Click "Next" and "Remove" as prompted.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000020: Windows Server 2016 must, at a minimum, offload audit records of interconnected systems in real time and offload standalone or nondomain-joined systems weekly.
Verify the audit records, at a minimum, are offloaded for interconnected systems in real time and offloaded for standalone or nondomain-joined systems weekly. If they are not, this is a finding.
Discussion
Protection of log data includes ensuring the log data is not accidentally lost or deleted. Audit information stored in one location is vulnerable to accidental or incidental deletion or alteration.
Fix
Configure the system to, at a minimum, offload audit records of interconnected systems in real time and offload standalone or nondomain-joined systems weekly.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000390: The Deny log on as a service user right must be configured to include no accounts or groups (blank) on domain controllers.
This applies to domain controllers. A separate version applies to other systems. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups are defined for the "Deny log on as a service" user right, this is a finding. For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs are granted the "SeDenyServiceLogonRight" user right, this is a finding.
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Deny log on as a service" user right defines accounts that are denied logon as a service. Incorrect configurations could prevent services from starting and result in a denial of service.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Deny log on as a service" to include no entries (blank).
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-MS-000390: The "Deny log on as a service" user right on member servers must be configured to prevent access from highly privileged domain accounts on domain systems. No other groups or accounts must be assigned this right.
This applies to member servers. A separate version applies to domain controllers. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If the following accounts or groups are not defined for the "Deny log on as a service" user right on domain-joined systems, this is a finding. - Enterprise Admins Group - Domain Admins Group If any accounts or groups are defined for the "Deny log on as a service" user right on nondomain-joined systems, this is a finding. For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If the following SIDs are not defined for the "SeDenyServiceLogonRight" user right on domain-joined systems, this is a finding. S-1-5-root domain-519 (Enterprise Admins) S-1-5-domain-512 (Domain Admins)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Deny log on as a service" user right defines accounts that are denied logon as a service. In an Active Directory Domain, denying logons to the Enterprise Admins and Domain Admins groups on lower-trust systems helps mitigate the risk of privilege escalation from credential theft attacks, which could lead to the compromise of an entire domain. Incorrect configurations could prevent services from starting and result in a denial of service.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Deny log on as a service" to include the following: Domain systems: - Enterprise Admins Group - Domain Admins Group
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000160: The Windows dialog box title for the legal banner must be configured with the appropriate text.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ Value Name: LegalNoticeCaption Value Type: REG_SZ Value: See message title options below "DoD Notice and Consent Banner", "US Department of Defense Warning Statement", or an organization-defined equivalent. If an organization-defined title is used, it can in no case contravene or modify the language of the banner text required in WN16-SO-000150. Automated tools may only search for the titles defined above. If an organization-defined title is used, a manual review will be required.
Discussion
Failure to display the logon banner prior to a logon attempt will negate legal proceedings resulting from unauthorized access to system resources. Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Interactive Logon: Message title for users attempting to log on" to "DoD Notice and Consent Banner", "US Department of Defense Warning Statement", or an organization-defined equivalent. If an organization-defined title is used, it can in no case contravene or modify the language of the message text required in WN16-SO-000150.
Rating Info
DISA Cat III. NIST impact 2.
Expert Comment
None
WN16-AC-000040: Windows Server 2016 password history must be configured to 24 passwords remembered.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Password Policy. If the value for "Enforce password history" is less than "24" passwords remembered, this is a finding. For server core installations, run the following command: Secedit /Export /Areas SecurityPolicy /CFG C:\Path\FileName.Txt If "PasswordHistorySize" is less than "24" in the file, this is a finding.
Discussion
A system is more vulnerable to unauthorized access when system users recycle the same password several times without being required to change to a unique password on a regularly scheduled basis. This enables users to effectively negate the purpose of mandating periodic password changes. The default value is "24" for Windows domain systems. DoD has decided this is the appropriate value for all Windows systems.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Password Policy >> "Enforce password history" to "24" passwords remembered.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000310: The Security event log size must be configured to 196608 KB or greater.
If the system is configured to write events directly to an audit server, this is NA. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\EventLog\Security\ Value Name: MaxSize Type: REG_DWORD Value: 0x00030000 (196608) (or greater)
Discussion
Inadequate log size will cause the log to fill up quickly. This may prevent audit events from being recorded properly and require frequent attention by administrative personnel.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Event Log Service >> Security >> "Specify the maximum log file size (KB)" to "Enabled" with a "Maximum Log Size (KB)" of "196608" or greater.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000480: Automatically signing in the last interactive user after a system-initiated restart must be disabled.
Verify the registry value below. If it does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ Value Name: DisableAutomaticRestartSignOn Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Windows can be configured to automatically sign the user back in after a Windows Update restart. Some protections are in place to help ensure this is done in a secure fashion; however, disabling this will prevent the caching of credentials for this purpose and also ensure the user is aware of the restart.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Windows Logon Options >> "Sign-in last interactive user automatically after a system-initiated restart" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000070: Permissions on the Active Directory data files must only allow System and Administrators access.
This applies to domain controllers. It is NA for other systems. Run "Regedit". Navigate to "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Parameters". Note the directory locations in the values for: Database log files path DSA Database file By default, they will be \Windows\NTDS. If the locations are different, the following will need to be run for each. Open "Command Prompt (Admin)". Navigate to the NTDS directory (\Windows\NTDS by default). Run "icacls *.*". If the permissions on each file are not as restrictive as the following, this is a finding. NT AUTHORITY\SYSTEM:(I)(F) BUILTIN\Administrators:(I)(F) (I) - permission inherited from parent container (F) - full access
Discussion
Improper access permissions for directory data-related files could allow unauthorized users to read, modify, or delete directory data or audit trails.
Fix
Maintain the permissions on NTDS database and log files as follows: NT AUTHORITY\SYSTEM:(I)(F) BUILTIN\Administrators:(I)(F) (I) - permission inherited from parent container (F) - full access
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-SO-000240: The setting Microsoft network server: Digitally sign communications (if client agrees) must be configured to Enabled.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\LanManServer\Parameters\ Value Name: EnableSecuritySignature Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
The server message block (SMB) protocol provides the basis for many network operations. Digitally signed SMB packets aid in preventing man-in-the-middle attacks. If this policy is enabled, the SMB server will negotiate SMB packet signing as requested by the client. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Microsoft network server: Digitally sign communications (if client agrees)" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000280: Systems requiring data at rest protections must employ cryptographic mechanisms to prevent unauthorized disclosure and modification of the information at rest.
Verify systems that require additional protections due to factors such as inadequate physical protection or sensitivity of the data employ encryption to protect the confidentiality and integrity of all information at rest. If they do not, this is a finding.
Discussion
This requirement addresses protection of user-generated data as well as operating system-specific configuration data. Organizations may choose to employ different mechanisms to achieve confidentiality and integrity protections, as appropriate, in accordance with the security category and/or classification of the information. Selection of a cryptographic mechanism is based on the need to protect the integrity of organizational information. The strength of the mechanism is commensurate with the security category and/or classification of the information. Organizations have the flexibility to either encrypt all information on storage devices (i.e., full disk encryption) or encrypt specific data structures (e.g., files, records, or fields). Satisfies: SRG-OS-000185-GPOS-00079, SRG-OS-000404-GPOS-00183, SRG-OS-000405-GPOS-00184
Fix
Configure systems that require additional protections due to factors such as inadequate physical protection or sensitivity of the data to employ encryption to protect the confidentiality and integrity of all information at rest.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-AU-000340: Windows Server 2016 must be configured to audit Policy Change - Authorization Policy Change successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Policy Change >> Authorization Policy Change - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Authorization Policy Change records events related to changes in user rights, such as "Create a token object". Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000064-GPOS-00033, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Policy Change >> "Audit Authorization Policy Change" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-MS-000400: The "Deny log on locally" user right on member servers must be configured to prevent access from highly privileged domain accounts on domain systems and from unauthenticated access on all systems.
This applies to member servers and standalone or nondomain-joined systems. A separate version applies to domain controllers. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If the following accounts or groups are not defined for the "Deny log on locally" user right, this is a finding. Domain Systems Only: - Enterprise Admins Group - Domain Admins Group All Systems: - Guests Group For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If the following SIDs are not defined for the "SeDenyInteractiveLogonRight" user right, this is a finding. Domain Systems Only: S-1-5-root domain-519 (Enterprise Admins) S-1-5-domain-512 (Domain Admins) All Systems: S-1-5-32-546 (Guests)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Deny log on locally" user right defines accounts that are prevented from logging on interactively. In an Active Directory Domain, denying logons to the Enterprise Admins and Domain Admins groups on lower-trust systems helps mitigate the risk of privilege escalation from credential theft attacks, which could lead to the compromise of an entire domain. The Guests group must be assigned this right to prevent unauthenticated access.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Deny log on locally" to include the following: Domain Systems Only: - Enterprise Admins Group - Domain Admins Group All Systems: - Guests Group
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-MS-000380: The "Deny log on as a batch job" user right on member servers must be configured to prevent access from highly privileged domain accounts on domain systems and from unauthenticated access on all systems.
This applies to member servers and standalone or nondomain-joined systems. A separate version applies to domain controllers. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If the following accounts or groups are not defined for the "Deny log on as a batch job" user right, this is a finding. Domain Systems Only: - Enterprise Admins Group - Domain Admins Group All Systems: - Guests Group For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If the following SIDs are not defined for the "SeDenyBatchLogonRight" user right, this is a finding. Domain Systems Only: S-1-5-root domain-519 (Enterprise Admins) S-1-5-domain-512 (Domain Admins) All Systems: S-1-5-32-546 (Guests)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Deny log on as a batch job" user right defines accounts that are prevented from logging on to the system as a batch job, such as Task Scheduler. In an Active Directory Domain, denying logons to the Enterprise Admins and Domain Admins groups on lower-trust systems helps mitigate the risk of privilege escalation from credential theft attacks, which could lead to the compromise of an entire domain. The Guests group must be assigned to prevent unauthenticated access.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Deny log on as a batch job" to include the following: Domain Systems Only: - Enterprise Admins Group - Domain Admins Group All Systems: - Guests Group
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000230: The Increase scheduling priority user right must only be assigned to the Administrators group.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Increase scheduling priority" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeIncreaseBasePriorityPrivilege" user right, this is a finding. S-1-5-32-544 (Administrators) If an application requires this user right, this would not be a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070).
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Increase scheduling priority" user right can change a scheduling priority, causing performance issues or a denial of service.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Increase scheduling priority" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000350: Windows Server 2016 must be configured to audit Privilege Use - Sensitive Privilege Use successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Privilege Use >> Sensitive Privilege Use - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Sensitive Privilege Use records events related to use of sensitive privileges, such as "Act as part of the operating system" or "Debug programs". Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000064-GPOS-00033, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Privilege Use >> "Audit Sensitive Privilege Use" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000290: Domain Controller PKI certificates must be issued by the DoD PKI or an approved External Certificate Authority (ECA).
This applies to domain controllers. It is NA for other systems. Run "MMC". Select "Add/Remove Snap-in" from the "File" menu. Select "Certificates" in the left pane and click the "Add >" button. Select "Computer Account" and click "Next". Select the appropriate option for "Select the computer you want this snap-in to manage" and click "Finish". Click "OK". Select and expand the Certificates (Local Computer) entry in the left pane. Select and expand the Personal entry in the left pane. Select the Certificates entry in the left pane. In the right pane, examine the "Issued By" field for the certificate to determine the issuing CA. If the "Issued By" field of the PKI certificate being used by the domain controller does not indicate the issuing CA is part of the DoD PKI or an approved ECA, this is a finding. If the certificates in use are issued by a CA authorized by the Component's CIO, this is a CAT II finding. There are multiple sources from which lists of valid DoD CAs and approved ECAs can be obtained: The Global Directory Service (GDS) website provides an online source. The address for this site is https://crl.gds.disa.mil. DoD Public Key Enablement (PKE) Engineering Support maintains the InstallRoot utility to manage DoD supported root certificates on Windows computers, which includes a list of authorized CAs. The utility package can be downloaded from the PKI and PKE Tools page on IASE: http://iase.disa.mil/pki-pke/function_pages/tools.html
Discussion
A PKI implementation depends on the practices established by the Certificate Authority (CA) to ensure the implementation is secure. Without proper practices, the certificates issued by a CA have limited value in authentication functions. The use of multiple CAs from separate PKI implementations results in interoperability issues. If servers and clients do not have a common set of root CA certificates, they are not able to authenticate each other.
Fix
Obtain a server certificate for the domain controller issued by the DoD PKI or an approved ECA.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-CC-000370: Passwords must not be saved in the Remote Desktop Client.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services\ Value Name: DisablePasswordSaving Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Saving passwords in the Remote Desktop Client could allow an unauthorized user to establish a remote desktop session to another system. The system must be configured to prevent users from saving passwords in the Remote Desktop Client. Satisfies: SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00156
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Remote Desktop Services >> Remote Desktop Connection Client >> "Do not allow passwords to be saved" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000410: The Deny log on through Remote Desktop Services user right on domain controllers must be configured to prevent unauthenticated access.
This applies to domain controllers. A separate version applies to other systems. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If the following accounts or groups are not defined for the "Deny log on through Remote Desktop Services" user right, this is a finding. - Guests Group For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If the following SID(s) are not defined for the "SeDenyRemoteInteractiveLogonRight" user right, this is a finding. S-1-5-32-546 (Guests)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Deny log on through Remote Desktop Services" user right defines the accounts that are prevented from logging on using Remote Desktop Services. The Guests group must be assigned this right to prevent unauthenticated access.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Deny log on through Remote Desktop Services" to include the following: - Guests Group
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000320: The System event log size must be configured to 32768 KB or greater.
If the system is configured to write events directly to an audit server, this is NA. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\EventLog\System\ Value Name: MaxSize Type: REG_DWORD Value: 0x00008000 (32768) (or greater)
Discussion
Inadequate log size will cause the log to fill up quickly. This may prevent audit events from being recorded properly and require frequent attention by administrative personnel.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Event Log Service >> System >> "Specify the maximum log file size (KB)" to "Enabled" with a "Maximum Log Size (KB)" of "32768" or greater.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000100: Windows Server 2016 must be configured to audit Account Management - Other Account Management Events successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Account Management >> Other Account Management Events - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Other Account Management Events records events such as the access of a password hash or the Password Policy Checking API being called. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000064-GPOS-00033, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Account Management >> "Audit Other Account Management Events" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000400: The Deny log on locally user right on domain controllers must be configured to prevent unauthenticated access.
This applies to domain controllers. A separate version applies to other systems. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If the following accounts or groups are not defined for the "Deny log on locally" user right, this is a finding. - Guests Group For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If the following SID(s) are not defined for the "SeDenyInteractiveLogonRight" user right, this is a finding. S-1-5-32-546 (Guests)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Deny log on locally" user right defines accounts that are prevented from logging on interactively. The Guests group must be assigned this right to prevent unauthenticated access.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Deny log on locally" to include the following: - Guests Group
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000100: Windows Server 2016 domain-joined systems must have a Trusted Platform Module (TPM) enabled and ready for use.
For standalone or nondomain-joined systems, this is NA. Verify the system has a TPM and it is ready for use. Run "tpm.msc". Review the sections in the center pane. "Status" must indicate it has been configured with a message such as "The TPM is ready for use" or "The TPM is on and ownership has been taken". TPM Manufacturer Information - Specific Version = 2.0 or 1.2 If a TPM is not found or is not ready for use, this is a finding.
Discussion
Credential Guard uses virtualization-based security to protect data that could be used in credential theft attacks if compromised. A number of system requirements must be met for Credential Guard to be configured and enabled properly. Without a TPM enabled and ready for use, Credential Guard keys are stored in a less secure method using software.
Fix
Ensure domain-joined systems have a TPM that is configured for use. (Versions 2.0 or 1.2 support Credential Guard.) The TPM must be enabled in the firmware. Run "tpm.msc" for configuration options in Windows.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000070: Manually managed application account passwords must be changed at least annually or when a system administrator with knowledge of the password leaves the organization.
Determine if manually managed application/service accounts exist. If none exist, this is NA. If passwords for manually managed application/service accounts are not changed at least annually or when an administrator with knowledge of the password leaves the organization, this is a finding. Identify manually managed application/service accounts. To determine the date a password was last changed: Domain controllers: Open "PowerShell". Enter "Get-AdUser -Identity [application account name] -Properties PasswordLastSet | FT Name, PasswordLastSet", where [application account name] is the name of the manually managed application/service account. If the "PasswordLastSet" date is more than one year old, this is a finding. Member servers and standalone or nondomain-joined systems: Open "Command Prompt". Enter 'Net User [application account name] | Find /i "Password Last Set"', where [application account name] is the name of the manually managed application/service account. If the "Password Last Set" date is more than one year old, this is a finding.
Discussion
Setting application account passwords to expire may cause applications to stop functioning. However, not changing them on a regular basis exposes them to attack. If managed service accounts are used, this alleviates the need to manually change application account passwords.
Fix
Change passwords for manually managed application/service accounts at least annually or when an administrator with knowledge of the password leaves the organization. It is recommended that system-managed service accounts be used whenever possible.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000100: The Active Directory Domain Controllers Organizational Unit (OU) object must have the proper access control permissions.
This applies to domain controllers. It is NA for other systems. Review the permissions on the Domain Controllers OU. Open "Active Directory Users and Computers" (available from various menus or run "dsa.msc"). Select "Advanced Features" in the "View" menu if not previously selected. Select the "Domain Controllers" OU (folder in folder icon). Right-click and select "Properties". Select the "Security" tab. If the permissions on the Domain Controllers OU do not restrict changes to System, Domain Admins, Enterprise Admins and Administrators, this is a finding. The default permissions listed below satisfy this requirement. Domains supporting Microsoft Exchange will have additional Exchange related permissions on the Domain Controllers OU. These may include some change related permissions and are not a finding. The permissions shown are at the summary level. More detailed permissions can be viewed by selecting the "Advanced" button, the desired Permission entry, and the "View" or "Edit" button. Except where noted otherwise, the special permissions may include a wide range of permissions and properties and are acceptable for this requirement. CREATOR OWNER - Special permissions SELF - Special permissions Authenticated Users - Read, Special permissions The special permissions for Authenticated Users are Read types. If detailed permissions include any Create, Delete, Modify, or Write Permissions or Properties, this is a finding. SYSTEM - Full Control Domain Admins - Read, Write, Create all child objects, Generate resultant set of policy (logging), Generate resultant set of policy (planning), Special permissions Enterprise Admins - Full Control Key Admins - Special permissions Enterprise Key Admins - Special permissions Administrators - Read, Write, Create all child objects, Generate resultant set of policy (logging), Generate resultant set of policy (planning), Special permissions Pre-Windows 2000 Compatible Access - Special permissions The Special permissions for Pre-Windows 2000 Compatible Access are Read types. If detailed permissions include any Create, Delete, Modify, or Write Permissions or Properties, this is a finding. ENTERPRISE DOMAIN CONTROLLERS - Read, Special permissions
Discussion
When Active Directory objects do not have appropriate access control permissions, it may be possible for malicious users to create, read, update, or delete the objects and degrade or destroy the integrity of the data. When the directory service is used for identification, authentication, or authorization functions, a compromise of the database objects could lead to a compromise of all systems that rely on the directory service. The Domain Controllers OU object requires special attention as the Domain Controllers are central to the configuration and management of the domain. Inappropriate access permissions defined for the Domain Controllers OU could allow an intruder or unauthorized personnel to make changes that could lead to the compromise of the domain.
Fix
Limit the permissions on the Domain Controllers OU to restrict changes to System, Domain Admins, Enterprise Admins and Administrators. The default permissions listed below satisfy this requirement. Domains supporting Microsoft Exchange will have additional Exchange related permissions on the Domain Controllers OU. These may include some change related permissions. CREATOR OWNER - Special permissions SELF - Special permissions Authenticated Users - Read, Special permissions The special permissions for Authenticated Users are Read types. SYSTEM - Full Control Domain Admins - Read, Write, Create all child objects, Generate resultant set of policy (logging), Generate resultant set of policy (planning), Special permissions Enterprise Admins - Full Control Key Admins - Special permissions Enterprise Key Admins - Special permissions Administrators - Read, Write, Create all child objects, Generate resultant set of policy (logging), Generate resultant set of policy (planning), Special permissions Pre-Windows 2000 Compatible Access - Special permissions The special permissions for Pre-Windows 2000 Compatible Access are Read types. ENTERPRISE DOMAIN CONTROLLERS - Read, Special permissions
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-MS-000310: Remote calls to the Security Account Manager (SAM) must be restricted to Administrators.
This applies to member servers and standalone or nondomain-joined systems. It is NA for domain controllers. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\Lsa\ Value Name: RestrictRemoteSAM Value Type: REG_SZ Value: O:BAG:BAD:(A;;RC;;;BA)
Discussion
The Windows Security Account Manager (SAM) stores users' passwords. Restricting Remote Procedure Call (RPC) connections to the SAM to Administrators helps protect those credentials.
Fix
Navigate to the policy Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network access: Restrict clients allowed to make remote calls to SAM". Select "Edit Security" to configure the "Security descriptor:". Add "Administrators" in "Group or user names:" if it is not already listed (this is the default). Select "Administrators" in "Group or user names:". Select "Allow" for "Remote Access" in "Permissions for "Administrators". Click "OK". The "Security descriptor:" must be populated with "O:BAG:BAD:(A;;RC;;;BA) for the policy to be enforced.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000420: Windows PowerShell 2.0 must not be installed.
Open "PowerShell". Enter "Get-WindowsFeature | Where Name -eq PowerShell-v2". If "Installed State" is "Installed", this is a finding. An Installed State of "Available" or "Removed" is not a finding.
Discussion
Windows PowerShell 5.0 added advanced logging features that can provide additional detail when malware has been run on a system. Disabling the Windows PowerShell 2.0 mitigates against a downgrade attack that evades the Windows PowerShell 5.0 script block logging feature.
Fix
Uninstall the "Windows PowerShell 2.0 Engine". Start "Server Manager". Select the server with the feature. Scroll down to "ROLES AND FEATURES" in the right pane. Select "Remove Roles and Features" from the drop-down "TASKS" list. Select the appropriate server on the "Server Selection" page and click "Next". Deselect "Windows PowerShell 2.0 Engine" under "Windows PowerShell" on the "Features" page. Click "Next" and "Remove" as prompted.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000360: File Explorer shell protocol must run in protected mode.
The default behavior is for shell protected mode to be turned on for File Explorer. If the registry value name below does not exist, this is not a finding. If it exists and is configured with a value of "0", this is not a finding. If it exists and is configured with a value of "1", this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\ Value Name: PreXPSP2ShellProtocolBehavior Value Type: REG_DWORD Value: 0x00000000 (0) (or if the Value Name does not exist)
Discussion
The shell protocol will limit the set of folders that applications can open when run in protected mode. Restricting files an application can open to a limited set of folders increases the security of Windows.
Fix
The default behavior is for shell protected mode to be turned on for File Explorer. If this needs to be corrected, configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> File Explorer >> "Turn off shell protocol protected mode" to "Not Configured" or "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000050: Audit policy using subcategories must be enabled.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\Lsa\ Value Name: SCENoApplyLegacyAuditPolicy Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. This setting allows administrators to enable more precise auditing capabilities.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-MS-000010: Only administrators responsible for the member server or standalone or nondomain-joined system must have Administrator rights on the system.
This applies to member servers and standalone or nondomain-joined systems. A separate version applies to domain controllers. Open "Computer Management". Navigate to "Groups" under "Local Users and Groups". Review the local "Administrators" group. Only administrator groups or accounts responsible for administration of the system may be members of the group. For domain-joined member servers, the Domain Admins group must be replaced by a domain member server administrator group. Standard user accounts must not be members of the local Administrator group. If accounts that do not have responsibility for administration of the system are members of the local Administrators group, this is a finding. If the built-in Administrator account or other required administrative accounts are found on the system, this is not a finding.
Discussion
An account that does not have Administrator duties must not have Administrator rights. Such rights would allow the account to bypass or modify required security restrictions on that machine and make it vulnerable to attack. System administrators must log on to systems using only accounts with the minimum level of authority necessary. For domain-joined member servers, the Domain Admins group must be replaced by a domain member server administrator group (refer to AD.0003 in the Active Directory Domain STIG). Restricting highly privileged accounts from the local Administrators group helps mitigate the risk of privilege escalation resulting from credential theft attacks. Standard user accounts must not be members of the built-in Administrators group.
Fix
Configure the local "Administrators" group to include only administrator groups or accounts responsible for administration of the system. For domain-joined member servers, replace the Domain Admins group with a domain member server administrator group. Remove any standard user accounts.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-AU-000285: Windows 2016 must be configured to audit Object Access - Other Object Access Events successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the "AuditPol" tool to review the current Audit Policy configuration: Open "PowerShell" or a "Command Prompt" with elevated privileges ("Run as Administrator"). Enter "AuditPol /get /category:*" Compare the "AuditPol" settings with the following: If the system does not audit the following, this is a finding. Object Access >> Other Object Access Events - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Auditing for other object access records events related to the management of task scheduler jobs and COM+ objects.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Object Access >> "Audit Other Object Access Events" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000320: Services using Local System that use Negotiate when reverting to NTLM authentication must use the computer identity instead of authenticating anonymously.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\LSA\ Value Name: UseMachineId Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Services using Local System that use Negotiate when reverting to NTLM authentication may gain unauthorized access if allowed to authenticate anonymously versus using the computer identity.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network security: Allow Local System to use computer identity for NTLM" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000420: Attachments must be prevented from being downloaded from RSS feeds.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Internet Explorer\Feeds\ Value Name: DisableEnclosureDownload Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Attachments from RSS feeds may not be secure. This setting will prevent attachments from being downloaded from RSS feeds.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> RSS Feeds >> "Prevent downloading of enclosures" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000030: The Kerberos service ticket maximum lifetime must be limited to 600 minutes or less.
This applies to domain controllers. It is NA for other systems. Verify the following is configured in the Default Domain Policy. Open "Group Policy Management". Navigate to "Group Policy Objects" in the Domain being reviewed (Forest >> Domains >> Domain). Right-click on the "Default Domain Policy". Select "Edit". Navigate to Computer Configuration >> Policies >> Windows Settings >> Security Settings >> Account Policies >> Kerberos Policy. If the value for "Maximum lifetime for service ticket" is "0" or greater than "600" minutes, this is a finding.
Discussion
This setting determines the maximum amount of time (in minutes) that a granted session ticket can be used to access a particular service. Session tickets are used only to authenticate new connections with servers. Ongoing operations are not interrupted if the session ticket used to authenticate the connection expires during the connection. Satisfies: SRG-OS-000112-GPOS-00057, SRG-OS-000113-GPOS-00058
Fix
Configure the policy value in the Default Domain Policy for Computer Configuration >> Policies >> Windows Settings >> Security Settings >> Account Policies >> Kerberos Policy >> "Maximum lifetime for service ticket" to a maximum of "600" minutes, but not "0", which equates to "Ticket doesn't expire".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000390: Windows Server 2016 must be configured to audit System - Other System Events successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*" Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. System >> Other System Events - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Audit Other System Events records information related to cryptographic key operations and the Windows Firewall service. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> System >> "Audit Other System Events" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000380: The Deny log on as a batch job user right on domain controllers must be configured to prevent unauthenticated access.
This applies to domain controllers. A separate version applies to other systems. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If the following accounts or groups are not defined for the "Deny log on as a batch job" user right, this is a finding. - Guests Group For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If the following SID(s) are not defined for the "SeDenyBatchLogonRight" user right, this is a finding. S-1-5-32-546 (Guests)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Deny log on as a batch job" user right defines accounts that are prevented from logging on to the system as a batch job, such as Task Scheduler. The Guests group must be assigned to prevent unauthenticated access.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Deny log on as a batch job" to include the following: - Guests Group
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000350: Kerberos encryption types must be configured to prevent the use of DES and RC4 encryption suites.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\Parameters\ Value Name: SupportedEncryptionTypes Value Type: REG_DWORD Value: 0x7ffffff8 (2147483640)
Discussion
Certain encryption types are no longer considered secure. The DES and RC4 encryption suites must not be used for Kerberos encryption. Note: Organizations with domain controllers running earlier versions of Windows where RC4 encryption is enabled, selecting "The other domain supports Kerberos AES Encryption" on domain trusts, may be required to allow client communication across the trust relationship.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network security: Configure encryption types allowed for Kerberos" to "Enabled" with only the following selected: AES128_HMAC_SHA1 AES256_HMAC_SHA1 Future encryption types Note: Organizations with domain controllers running earlier versions of Windows where RC4 encryption is enabled, selecting "The other domain supports Kerberos AES Encryption" on domain trusts, may be required to allow client communication across the trust relationship.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000380: The LAN Manager authentication level must be set to send NTLMv2 response only and to refuse LM and NTLM.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\Lsa\ Value Name: LmCompatibilityLevel Value Type: REG_DWORD Value: 0x00000005 (5)
Discussion
The Kerberos v5 authentication protocol is the default for authentication of users who are logging on to domain accounts. NTLM, which is less secure, is retained in later Windows versions for compatibility with clients and servers that are running earlier versions of Windows or applications that still use it. It is also used to authenticate logons to standalone or nondomain-joined computers that are running later versions.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network security: LAN Manager authentication level" to "Send NTLMv2 response only. Refuse LM & NTLM".
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-SO-000530: User Account Control must virtualize file and registry write failures to per-user locations.
UAC requirements are NA for Server Core installations (this is the default installation option for Windows Server 2016 versus Server with Desktop Experience) as well as Nano Server. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ Value Name: EnableVirtualization Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
User Account Control (UAC) is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting configures non-UAC-compliant applications to run in virtualized file and registry entries in per-user locations, allowing them to run.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "User Account Control: Virtualize file and registry write failures to per-user locations" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000260: The Manage auditing and security log user right must only be assigned to the Administrators group.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Manage auditing and security log" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeSecurityPrivilege" user right, this is a finding. S-1-5-32-544 (Administrators) If the organization has an Auditors group, the assignment of this group to the user right would not be a finding. If an application requires this user right, this would not be a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070).
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Manage auditing and security log" user right can manage the security log and change auditing configurations. This could be used to clear evidence of tampering. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000063-GPOS-00032, SRG-OS-000337-GPOS-00129
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Manage auditing and security log" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UC-000030: Zone information must be preserved when saving attachments.
The default behavior is for Windows to mark file attachments with their zone information. If the registry Value Name below does not exist, this is not a finding. If it exists and is configured with a value of "2", this is not a finding. If it exists and is configured with a value of "1", this is a finding. Registry Hive: HKEY_CURRENT_USER Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Attachments\ Value Name: SaveZoneInformation Value Type: REG_DWORD Value: 0x00000002 (2) (or if the Value Name does not exist)
Discussion
Attachments from outside sources may contain malicious code. Preserving zone of origin (Internet, intranet, local, restricted) information on file attachments allows Windows to determine risk.
Fix
The default behavior is for Windows to mark file attachments with their zone information. If this needs to be corrected, configure the policy value for User Configuration >> Administrative Templates >> Windows Components >> Attachment Manager >> "Do not preserve zone information in file attachments" to "Not Configured" or "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000210: The Generate security audits user right must only be assigned to Local Service and Network Service.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Generate security audits" user right, this is a finding. - Local Service - Network Service For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeAuditPrivilege" user right, this is a finding. S-1-5-19 (Local Service) S-1-5-20 (Network Service) If an application requires this user right, this would not be a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070).
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Generate security audits" user right specifies users and processes that can generate Security Log audit records, which must only be the system service accounts defined.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Generate security audits" to include only the following accounts or groups: - Local Service - Network Service
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000020: Local accounts with blank passwords must be restricted to prevent access from the network.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\Lsa\ Value Name: LimitBlankPasswordUse Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
An account without a password can allow unauthorized access to a system as only the username would be required. Password policies should prevent accounts with blank passwords from existing on a system. However, if a local account with a blank password does exist, enabling this setting will prevent network access, limiting the account to local console logon only.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Accounts: Limit local account use of blank passwords to console logon only" to "Enabled".
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-AU-000050: Permissions for the System event log must prevent access by non-privileged accounts.
Navigate to the System event log file. The default location is the "%SystemRoot%\System32\winevt\Logs" folder. However, the logs may have been moved to another folder. If the permissions for the "System.evtx" file are not as restrictive as the default permissions listed below, this is a finding. Eventlog - Full Control SYSTEM - Full Control Administrators - Full Control
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. The System event log may be susceptible to tampering if proper permissions are not applied. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029
Fix
Configure the permissions on the System event log file (System.evtx) to prevent access by non-privileged accounts. The default permissions listed below satisfy this requirement: Eventlog - Full Control SYSTEM - Full Control Administrators - Full Control The default location is the "%SystemRoot%\ System32\winevt\Logs" folder. If the location of the logs has been changed, when adding Eventlog to the permissions, it must be entered as "NT Service\Eventlog".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000150: Directory data (outside the root DSE) of a non-public directory must be configured to prevent anonymous access.
This applies to domain controllers. It is NA for other systems. Open "Command Prompt" (not elevated). Run "ldp.exe". From the "Connection menu", select "Bind". Clear the User, Password, and Domain fields. Select "Simple bind" for the Bind type and click "OK". Confirmation of anonymous access will be displayed at the end: res = ldap_simple_bind_s Authenticated as: 'NT AUTHORITY\ANONYMOUS LOGON' From the "Browse" menu, select "Search". In the Search dialog, enter the DN of the domain naming context (generally something like "dc=disaost,dc=mil") in the Base DN field. Clear the Attributes field and select "Run". Error messages should display related to Bind and user not authenticated. If attribute data is displayed, anonymous access is enabled to the domain naming context and this is a finding. The following network controls allow the finding severity to be downgraded to a CAT II since these measures lower the risk associated with anonymous access. Network hardware ports at the site are subject to 802.1x authentication or MAC address restrictions. Premise firewall or host restrictions prevent access to ports 389, 636, 3268, and 3269 from client hosts not explicitly identified by domain (.mil) or IP address.
Discussion
To the extent that anonymous access to directory data (outside the root DSE) is permitted, read access control of the data is effectively disabled. If other means of controlling access (such as network restrictions) are compromised, there may be nothing else to protect the confidentiality of sensitive directory data.
Fix
Configure directory data (outside the root DSE) of a non-public directory to prevent anonymous access. For AD, there are multiple configuration items that could enable anonymous access. Changing the access permissions on the domain naming context object (from the secure defaults) could enable anonymous access. If the check procedures indicate this is the cause, the process that was used to change the permissions should be reversed. This could have been through the Windows Support Tools ADSI Edit console (adsiedit.msc). The dsHeuristics option is used. This is addressed in check V-8555 in the AD Forest STIG.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-SO-000250: Anonymous SID/Name translation must not be allowed.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options. If the value for "Network access: Allow anonymous SID/Name translation" is not set to "Disabled", this is a finding. For server core installations, run the following command: Secedit /Export /Areas SecurityPolicy /CFG C:\Path\FileName.Txt If "LSAAnonymousNameLookup" equals "1" in the file, this is a finding.
Discussion
Allowing anonymous SID/Name translation can provide sensitive information for accessing a system. Only authorized users must be able to perform such translations.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network access: Allow anonymous SID/Name translation" to "Disabled".
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-00-000270: Software certificate installation files must be removed from Windows Server 2016.
Search all drives for *.p12 and *.pfx files. If any files with these extensions exist, this is a finding. This does not apply to server-based applications that have a requirement for .p12 certificate files or Adobe PreFlight certificate files. Some applications create files with extensions of .p12 that are not certificate installation files. Removal of non-certificate installation files from systems is not required. These must be documented with the ISSO.
Discussion
Use of software certificates and their accompanying installation files for end users to access resources is less secure than the use of hardware-based certificates.
Fix
Remove any certificate installation files (*.p12 and *.pfx) found on a system. Note: This does not apply to server-based applications that have a requirement for .p12 certificate files or Adobe PreFlight certificate files.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000240: Windows Server 2016 must be configured to audit DS Access - Directory Service Access successes.
This applies to domain controllers. It is NA for other systems. Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. DS Access >> Directory Service Access - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Audit Directory Service Access records events related to users accessing an Active Directory object. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> DS Access >> "Directory Service Access" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AC-000030: Windows Server 2016 must have the period of time before the bad logon counter is reset configured to 15 minutes or greater.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Account Lockout Policy. If the "Reset account lockout counter after" value is less than "15" minutes, this is a finding. For server core installations, run the following command: Secedit /Export /Areas SecurityPolicy /CFG C:\Path\FileName.Txt If "ResetLockoutCount" is less than "15" in the file, this is a finding.
Discussion
The account lockout feature, when enabled, prevents brute-force password attacks on the system. This parameter specifies the period of time that must pass after failed logon attempts before the counter is reset to "0". The smaller this value is, the less effective the account lockout feature will be in protecting the local system. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Account Lockout Policy >> "Reset account lockout counter after" to at least "15" minutes.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000110: The Create permanent shared objects user right must not be assigned to any groups or accounts.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups are granted the "Create permanent shared objects" user right, this is a finding. For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs are granted the "SeCreatePermanentPrivilege" user right, this is a finding.
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Create permanent shared objects" user right could expose sensitive data by creating shared objects.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Create permanent shared objects" to be defined but containing no entries (blank).
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000210: Outdated or unused accounts must be removed from the system or disabled.
Open "Windows PowerShell". Domain Controllers: Enter "Search-ADAccount -AccountInactive -UsersOnly -TimeSpan 35.00:00:00" This will return accounts that have not been logged on to for 35 days, along with various attributes such as the Enabled status and LastLogonDate. Member servers and standalone or nondomain-joined systems: Copy or enter the lines below to the PowerShell window and enter. (Entering twice may be required. Do not include the quotes at the beginning and end of the query.) "([ADSI]('WinNT://{0}' -f $env:COMPUTERNAME)).Children | Where { $_.SchemaClassName -eq 'user' } | ForEach { $user = ([ADSI]$_.Path) $lastLogin = $user.Properties.LastLogin.Value $enabled = ($user.Properties.UserFlags.Value -band 0x2) -ne 0x2 if ($lastLogin -eq $null) { $lastLogin = 'Never' } Write-Host $user.Name $lastLogin $enabled }" This will return a list of local accounts with the account name, last logon, and if the account is enabled (True/False). For example: User1 10/31/2015 5:49:56 AM True Review the list of accounts returned by the above queries to determine the finding validity for each account reported. Exclude the following accounts: - Built-in administrator account (Renamed, SID ending in 500) - Built-in guest account (Renamed, Disabled, SID ending in 501) - Built-in default account (Renamed, Disabled, SID ending in 503) - Application accounts If any enabled accounts have not been logged on to within the past 35 days, this is a finding. Inactive accounts that have been reviewed and deemed to be required must be documented with the ISSO.
Discussion
Outdated or unused accounts provide penetration points that may go undetected. Inactive accounts must be deleted if no longer necessary or, if still required, disabled until needed. Satisfies: SRG-OS-000104-GPOS-00051, SRG-OS-000118-GPOS-00060
Fix
Regularly review accounts to determine if they are still active. Remove or disable accounts that have not been used in the last 35 days.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000210: Unencrypted passwords must not be sent to third-party Server Message Block (SMB) servers.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters\ Value Name: EnablePlainTextPassword Value Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Some non-Microsoft SMB servers only support unencrypted (plain-text) password authentication. Sending plain-text passwords across the network when authenticating to an SMB server reduces the overall security of the environment. Check with the vendor of the SMB server to determine if there is a way to support encrypted password authentication.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Microsoft Network Client: Send unencrypted password to third-party SMB servers" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000230: Windows Server 2016 must be configured to audit Account Management - Computer Account Management successes.
This applies to domain controllers. It is NA for other systems. Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Account Management >> Computer Account Management - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Computer Account Management records events such as creating, changing, deleting, renaming, disabling, or enabling computer accounts. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000476-GPOS-00221
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Account Management >> "Audit Computer Account Management" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000360: The Allow log on through Remote Desktop Services user right must only be assigned to the Administrators group.
This applies to domain controllers, it is NA for other systems. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Allow log on through Remote Desktop Services" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeRemoteInteractiveLogonRight" user right, this is a finding. S-1-5-32-544 (Administrators)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Allow log on through Remote Desktop Services" user right can access a system through Remote Desktop.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Allow log on through Remote Desktop Services" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-MS-000340: The "Access this computer from the network" user right must only be assigned to the Administrators and Authenticated Users groups on member servers.
This applies to member servers and standalone or nondomain-joined systems. A separate version applies to domain controllers. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Access this computer from the network" user right, this is a finding. - Administrators - Authenticated Users For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeNetworkLogonRight" user right, this is a finding. S-1-5-32-544 (Administrators) S-1-5-11 (Authenticated Users) If an application requires this user right, this would not be a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070).
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Access this computer from the network" user right may access resources on the system, and this right must be limited to those requiring it.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Access this computer from the network" to include only the following accounts or groups: - Administrators - Authenticated Users
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000180: Permissions for the Windows installation directory must conform to minimum requirements.
The default permissions are adequate when the Security Option "Network access: Let everyone permissions apply to anonymous users" is set to "Disabled" (WN16-SO-000290). Review the permissions for the Windows installation directory (usually C:\Windows). Non-privileged groups such as Users or Authenticated Users must not have greater than "Read & execute" permissions. (Individual accounts must not be used to assign permissions.) If permissions are not as restrictive as the default permissions listed below, this is a finding. Viewing in File Explorer: For each folder, view the Properties. Select the "Security" tab and the "Advanced" button. Default permissions: \Windows Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to TrustedInstaller - Full control - This folder and subfolders SYSTEM - Modify - This folder only SYSTEM - Full control - Subfolders and files only Administrators - Modify - This folder only Administrators - Full control - Subfolders and files only Users - Read & execute - This folder, subfolders, and files CREATOR OWNER - Full control - Subfolders and files only ALL APPLICATION PACKAGES - Read & execute - This folder, subfolders, and files ALL RESTRICTED APPLICATION PACKAGES - Read & execute - This folder, subfolders, and files Alternately, use icacls: Open a Command prompt (admin). Enter "icacls" followed by the directory: "icacls c:\windows" The following results should be displayed for each when entered: c:\windows NT SERVICE\TrustedInstaller:(F) NT SERVICE\TrustedInstaller:(CI)(IO)(F) NT AUTHORITY\SYSTEM:(M) NT AUTHORITY\SYSTEM:(OI)(CI)(IO)(F) BUILTIN\Administrators:(M) BUILTIN\Administrators:(OI)(CI)(IO)(F) BUILTIN\Users:(RX) BUILTIN\Users:(OI)(CI)(IO)(GR,GE) CREATOR OWNER:(OI)(CI)(IO)(F) APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(RX) APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(OI)(CI)(IO)(GR,GE) APPLICATION PACKAGE AUTHORITY\ALL RESTRICTED APPLICATION PACKAGES:(RX) APPLICATION PACKAGE AUTHORITY\ALL RESTRICTED APPLICATION PACKAGES:(OI)(CI)(IO)(GR,GE) Successfully processed 1 files; Failed processing 0 files
Discussion
Changing the system's file and directory permissions allows the possibility of unauthorized and anonymous modification to the operating system and installed applications. The default permissions are adequate when the Security Option "Network access: Let everyone permissions apply to anonymous users" is set to "Disabled" (WN16-SO-000290). Satisfies: SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000312-GPOS-00124
Fix
Maintain the default file ACLs and configure the Security Option "Network access: Let everyone permissions apply to anonymous users" to "Disabled" (WN16-SO-000290). Default permissions: Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to TrustedInstaller - Full control - This folder and subfolders SYSTEM - Modify - This folder only SYSTEM - Full control - Subfolders and files only Administrators - Modify - This folder only Administrators - Full control - Subfolders and files only Users - Read & execute - This folder, subfolders, and files CREATOR OWNER - Full control - Subfolders and files only ALL APPLICATION PACKAGES - Read & execute - This folder, subfolders, and files ALL RESTRICTED APPLICATION PACKAGES - Read & execute - This folder, subfolders, and files
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000220: Windows Server 2016 accounts must require passwords.
Review the password required status for enabled user accounts. Open "PowerShell". Domain Controllers: Enter "Get-Aduser -Filter * -Properties Passwordnotrequired |FT Name, Passwordnotrequired, Enabled". Exclude disabled accounts (e.g., DefaultAccount, Guest) and Trusted Domain Objects (TDOs). If "Passwordnotrequired" is "True" or blank for any enabled user account, this is a finding. Member servers and standalone or nondomain-joined systems: Enter 'Get-CimInstance -Class Win32_Useraccount -Filter "PasswordRequired=False and LocalAccount=True" | FT Name, PasswordRequired, Disabled, LocalAccount'. Exclude disabled accounts (e.g., DefaultAccount, Guest). If any enabled user accounts are returned with a "PasswordRequired" status of "False", this is a finding.
Discussion
The lack of password protection enables anyone to gain access to the information system, which opens a backdoor opportunity for intruders to compromise the system as well as other resources. Accounts on a system must require passwords.
Fix
Configure all enabled user accounts to require passwords. The password required flag can be set by entering the following on a command line: "Net user [username] /passwordreq:yes", substituting [username] with the name of the user account.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000060: Event Viewer must be protected from unauthorized modification and deletion.
Navigate to "%SystemRoot%\System32". View the permissions on "Eventvwr.exe". If any groups or accounts other than TrustedInstaller have "Full control" or "Modify" permissions, this is a finding. The default permissions below satisfy this requirement: TrustedInstaller - Full Control Administrators, SYSTEM, Users, ALL APPLICATION PACKAGES, ALL RESTRICTED APPLICATION PACKAGES - Read & Execute
Discussion
Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. Operating systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys in order to make access decisions regarding the modification or deletion of audit tools. Satisfies: SRG-OS-000257-GPOS-00098, SRG-OS-000258-GPOS-00099
Fix
Configure the permissions on the "Eventvwr.exe" file to prevent modification by any groups or accounts other than TrustedInstaller. The default permissions listed below satisfy this requirement: TrustedInstaller - Full Control Administrators, SYSTEM, Users, ALL APPLICATION PACKAGES, ALL RESTRICTED APPLICATION PACKAGES - Read & Execute The default location is the "%SystemRoot%\ System32" folder.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000280: Domain controllers must have a PKI server certificate.
This applies to domain controllers. It is NA for other systems. Run "MMC". Select "Add/Remove Snap-in" from the "File" menu. Select "Certificates" in the left pane and click the "Add >" button. Select "Computer Account" and click "Next". Select the appropriate option for "Select the computer you want this snap-in to manage" and click "Finish". Click "OK". Select and expand the Certificates (Local Computer) entry in the left pane. Select and expand the Personal entry in the left pane. Select the Certificates entry in the left pane. If no certificate for the domain controller exists in the right pane, this is a finding.
Discussion
Domain controllers are part of the chain of trust for PKI authentications. Without the appropriate certificate, the authenticity of the domain controller cannot be verified. Domain controllers must have a server certificate to establish authenticity as part of PKI authentications in the domain.
Fix
Obtain a server certificate for the domain controller.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000450: The time service must synchronize with an appropriate DoD time source.
Review the Windows time service configuration. Open an elevated "Command Prompt" (run as administrator). Enter "W32tm /query /configuration". Domain-joined systems (excluding the domain controller with the PDC emulator role): If the value for "Type" under "NTP Client" is not "NT5DS", this is a finding. Other systems: If systems are configured with a "Type" of "NTP", including standalone or nondomain-joined systems and the domain controller with the PDC Emulator role, and do not have a DoD time server defined for "NTPServer", this is a finding. To determine the domain controller with the PDC Emulator role: Open "PowerShell". Enter "Get-ADDomain | FT PDCEmulator".
Discussion
The Windows Time Service controls time synchronization settings. Time synchronization is essential for authentication and auditing purposes. If the Windows Time Service is used, it must synchronize with a secure, authorized time source. Domain-joined systems are automatically configured to synchronize with domain controllers. If an NTP server is configured, it must synchronize with a secure, authorized time source.
Fix
Configure the system to synchronize time with an appropriate DoD time source. Domain-joined systems use NT5DS to synchronize time from other systems in the domain by default. If the system needs to be configured to an NTP server, configure the system to point to an authorized time server by setting the policy value for Computer Configuration >> Administrative Templates >> System >> Windows Time Service >> Time Providers >> "Configure Windows NTP Client" to "Enabled", and configure the "NtpServer" field to point to an appropriate DoD time server. The US Naval Observatory operates stratum 1 time servers, which are identified at: https://www.cnmoc.usff.navy.mil/Our-Commands/United-States-Naval-Observatory/Precise-Time-Department/Network-Time-Protocol-NTP/ Time synchronization will occur through a hierarchy of time servers down to the local level. Clients and lower-level servers will synchronize with an authorized time server in the hierarchy.
Rating Info
DISA Cat III. NIST impact 2.
Expert Comment
None
WN16-AU-000320: Windows Server 2016 must be configured to audit Policy Change - Audit Policy Change failures.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Policy Change >> Audit Policy Change - Failure
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Audit Policy Change records events related to changes in audit policy. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Policy Change >> "Audit Audit Policy Change" with "Failure" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000340: PKU2U authentication using online identities must be prevented.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\LSA\pku2u\ Value Name: AllowOnlineID Type: REG_DWORD Value: 0x00000000 (0)
Discussion
PKU2U is a peer-to-peer authentication protocol. This setting prevents online identities from authenticating to domain-joined systems. Authentication will be centrally managed with Windows user accounts.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network security: Allow PKU2U authentication requests to this computer to use online identities" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000260: Windows Server 2016 must be configured to audit DS Access - Directory Service Changes successes.
This applies to domain controllers. It is NA for other systems. Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. DS Access >> Directory Service Changes - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Audit Directory Service Changes records events related to changes made to objects in Active Directory Domain Services. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> DS Access >> "Directory Service Changes" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000370: The Deny access to this computer from the network user right on domain controllers must be configured to prevent unauthenticated access.
This applies to domain controllers. A separate version applies to other systems. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If the following accounts or groups are not defined for the "Deny access to this computer from the network" user right, this is a finding. - Guests Group For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If the following SIDs are not defined for the "SeDenyNetworkLogonRight" user right, this is a finding. S-1-5-32-546 (Guests)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Deny access to this computer from the network" user right defines the accounts that are prevented from logging on from the network. The Guests group must be assigned this right to prevent unauthenticated access.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Deny access to this computer from the network" to include the following: - Guests Group
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-MS-000370: The "Deny access to this computer from the network" user right on member servers must be configured to prevent access from highly privileged domain accounts and local accounts on domain systems and from unauthenticated access on all systems.
This applies to member servers and standalone or nondomain-joined systems. A separate version applies to domain controllers. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If the following accounts or groups are not defined for the "Deny access to this computer from the network" user right, this is a finding. Domain Systems Only: - Enterprise Admins group - Domain Admins group - "Local account and member of Administrators group" or "Local account" (see Note below) All Systems: - Guests group For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If the following SIDs are not defined for the "SeDenyNetworkLogonRight" user right, this is a finding. Domain Systems Only: S-1-5-root domain-519 (Enterprise Admins) S-1-5-domain-512 (Domain Admins) S-1-5-114 ("Local account and member of Administrators group") or S-1-5-113 ("Local account") All Systems: S-1-5-32-546 (Guests) Note: These are built-in security groups. "Local account" is more restrictive but may cause issues on servers such as systems that provide failover clustering.
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Deny access to this computer from the network" user right defines the accounts that are prevented from logging on from the network. In an Active Directory Domain, denying logons to the Enterprise Admins and Domain Admins groups on lower-trust systems helps mitigate the risk of privilege escalation from credential theft attacks, which could lead to the compromise of an entire domain. Local accounts on domain-joined systems must also be assigned this right to decrease the risk of lateral movement resulting from credential theft attacks. The Guests group must be assigned this right to prevent unauthenticated access.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Deny access to this computer from the network" to include the following: Domain Systems Only: - Enterprise Admins group - Domain Admins group - "Local account and member of Administrators group" or "Local account" (see Note below) All Systems: - Guests group Note: These are built-in security groups. "Local account" is more restrictive but may cause issues on servers such as systems that provide failover clustering.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000550: The Windows Remote Management (WinRM) service must not store RunAs credentials.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\WinRM\Service\ Value Name: DisableRunAs Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Storage of administrative credentials could allow unauthorized access. Disallowing the storage of RunAs credentials for Windows Remote Management will prevent them from being used with plug-ins. Satisfies: SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00156
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Windows Remote Management (WinRM) >> WinRM Service >> "Disallow WinRM from storing RunAs credentials" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000450: Windows Server 2016 must be configured to audit System - System Integrity failures.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. System >> System Integrity - Failure
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. System Integrity records events related to violations of integrity to the security subsystem. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000471-GPOS-00215, SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> System >> "Audit System Integrity" with "Failure" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-MS-000040: Unauthenticated Remote Procedure Call (RPC) clients must be restricted from connecting to the RPC server.
This applies to member servers and standalone or nondomain-joined systems. It is NA for domain controllers. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows NT\Rpc\ Value Name: RestrictRemoteClients Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Unauthenticated RPC clients may allow anonymous access to sensitive information. Configuring RPC to restrict unauthenticated RPC clients from connecting to the RPC server will prevent anonymous connections.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> System >> Remote Procedure Call >> "Restrict Unauthenticated RPC clients" to "Enabled" with "Authenticated" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000220: The Active Directory RID Manager$ object must be configured with proper audit settings.
This applies to domain controllers. It is NA for other systems. Review the auditing configuration for the "RID Manager$" object. Open "Active Directory Users and Computers" (available from various menus or run "dsa.msc"). Ensure "Advanced Features" is selected in the "View" menu. Select "System" under the domain being reviewed in the left pane. Right-click the "RID Manager$" object in the right pane and select "Properties". Select the "Security" tab. Select the "Advanced" button and then the "Auditing" tab. If the audit settings on the "RID Manager$" object are not at least as inclusive as those below, this is a finding. Type - Fail Principal - Everyone Access - Full Control Inherited from - None The success types listed below are defaults. Where Special is listed in the summary screens for Access, detailed Permissions are provided for reference. Various Properties selections may also exist by default. Type - Success Principal - Everyone Access - Special Inherited from - None (Access - Special = Write all properties, All extended rights, Change RID master) Two instances with the following summary information will be listed. Type - Success Principal - Everyone Access - (blank) Inherited from - (CN of domain)
Discussion
When inappropriate audit settings are configured for directory service database objects, it may be possible for a user or process to update the data without generating any tracking data. The impact of missing audit data is related to the type of object. A failure to capture audit data for objects used by identification, authentication, or authorization functions could degrade or eliminate the ability to track changes to access policy for systems or data. For Active Directory (AD), there are a number of critical object types in the domain naming context of the AD database for which auditing is essential. This includes the RID Manager$ object. Because changes to these objects can significantly impact access controls or the availability of systems, the absence of auditing data makes it impossible to identify the source of changes that impact the confidentiality, integrity, and availability of data and systems throughout an AD domain. The lack of proper auditing can result in insufficient forensic evidence needed to investigate an incident and prosecute the intruder. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Open "Active Directory Users and Computers" (available from various menus or run "dsa.msc"). Ensure "Advanced Features" is selected in the "View" menu. Select "System" under the domain being reviewed in the left pane. Right-click the "RID Manager$" object in the right pane and select "Properties". Select the "Security" tab. Select the "Advanced" button and then the "Auditing" tab. Configure the audit settings for RID Manager$ object to include the following. Type - Fail Principal - Everyone Access - Full Control Inherited from - None The success types listed below are defaults. Where Special is listed in the summary screens for Access, detailed Permissions are provided for reference. Various Properties selections may also exist by default. Type - Success Principal - Everyone Access - Special Inherited from - None (Access - Special = Write all properties, All extended rights, Change RID master) Two instances with the following summary information will be listed. Type - Success Principal - Everyone Access - (blank) Inherited from - (CN of domain)
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000340: Explorer Data Execution Prevention must be enabled.
The default behavior is for Data Execution Prevention to be turned on for File Explorer. If the registry value name below does not exist, this is not a finding. If it exists and is configured with a value of "0", this is not a finding. If it exists and is configured with a value of "1", this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\Explorer\ Value Name: NoDataExecutionPrevention Value Type: REG_DWORD Value: 0x00000000 (0) (or if the Value Name does not exist)
Discussion
Data Execution Prevention provides additional protection by performing checks on memory to help prevent malicious code from running. This setting will prevent Data Execution Prevention from being turned off for File Explorer.
Fix
The default behavior is for data execution prevention to be turned on for File Explorer. If this needs to be corrected, configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> File Explorer >> "Turn off Data Execution Prevention for Explorer" to "Not Configured" or "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000440: Indexing of encrypted files must be turned off.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\Windows Search\ Value Name: AllowIndexingEncryptedStoresOrItems Value Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Indexing of encrypted files may expose sensitive data. This setting prevents encrypted files from being indexed.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Search >> "Allow indexing of encrypted files" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000450: Users must be prevented from changing installation options.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\Installer\ Value Name: EnableUserControl Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Installation options for applications are typically controlled by administrators. This setting prevents users from changing installation options that may bypass security features.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Windows Installer >> "Allow user control over installs" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000120: The Create symbolic links user right must only be assigned to the Administrators group.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Create symbolic links" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeCreateSymbolicLinkPrivilege" user right, this is a finding. S-1-5-32-544 (Administrators) Systems that have the Hyper-V role will also have "Virtual Machines" given this user right (this may be displayed as "NT Virtual Machine\Virtual Machines", SID S-1-5-83-0). This is not a finding.
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Create symbolic links" user right can create pointers to other objects, which could expose the system to attack.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Create symbolic links" to include only the following accounts or groups: - Administrators Systems that have the Hyper-V role will also have "Virtual Machines" given this user right. If this needs to be added manually, enter it as "NT Virtual Machine\Virtual Machines".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000360: The Microsoft FTP service must not be installed unless required.
If the server has the role of an FTP server, this is NA. Open "PowerShell". Enter "Get-WindowsFeature | Where Name -eq Web-Ftp-Service". If "Installed State" is "Installed", this is a finding. An Installed State of "Available" or "Removed" is not a finding. If the system has the role of an FTP server, this must be documented with the ISSO.
Discussion
Unnecessary services increase the attack surface of a system. Some of these services may not support required levels of authentication or encryption.
Fix
Uninstall the "FTP Server" role. Start "Server Manager". Select the server with the role. Scroll down to "ROLES AND FEATURES" in the right pane. Select "Remove Roles and Features" from the drop-down "TASKS" list. Select the appropriate server on the "Server Selection" page and click "Next". Deselect "FTP Server" under "Web Server (IIS)" on the "Roles" page. Click "Next" and "Remove" as prompted.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-MS-000050: Caching of logon credentials must be limited.
This applies to member servers. For domain controllers and standalone or nondomain-joined systems, this is NA. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\ Value Name: CachedLogonsCount Value Type: REG_SZ Value: 4 (or less)
Discussion
The default Windows configuration caches the last logon credentials for users who log on interactively to a system. This feature is provided for system availability reasons, such as the user's machine being disconnected from the network or domain controllers being unavailable. Even though the credential cache is well protected, if a system is attacked, an unauthorized individual may isolate the password to a domain user account using a password-cracking program and gain access to the domain.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Interactive Logon: Number of previous logons to cache (in case Domain Controller is not available)" to "4" logons or less.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000060: The computer clock synchronization tolerance must be limited to 5 minutes or less.
This applies to domain controllers. It is NA for other systems. Verify the following is configured in the Default Domain Policy. Open "Group Policy Management". Navigate to "Group Policy Objects" in the Domain being reviewed (Forest >> Domains >> Domain). Right-click on the "Default Domain Policy". Select "Edit". Navigate to Computer Configuration >> Policies >> Windows Settings >> Security Settings >> Account Policies >> Kerberos Policy. If the "Maximum tolerance for computer clock synchronization" is greater than "5" minutes, this is a finding.
Discussion
This setting determines the maximum time difference (in minutes) that Kerberos will tolerate between the time on a client's clock and the time on a server's clock while still considering the two clocks synchronous. In order to prevent replay attacks, Kerberos uses timestamps as part of its protocol definition. For timestamps to work properly, the clocks of the client and the server need to be in sync as much as possible. Satisfies: SRG-OS-000112-GPOS-00057, SRG-OS-000113-GPOS-00058
Fix
Configure the policy value in the Default Domain Policy for Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Kerberos Policy >> "Maximum tolerance for computer clock synchronization" to a maximum of "5" minutes or less.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000450: The default permissions of global system objects must be strengthened.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\Session Manager\ Value Name: ProtectionMode Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Windows systems maintain a global list of shared system resources such as DOS device names, mutexes, and semaphores. Each type of object is created with a default Discretionary Access Control List (DACL) that specifies who can access the objects with what permissions. When this policy is enabled, the default DACL is stronger, allowing non-administrative users to read shared objects but not to modify shared objects they did not create.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "System objects: Strengthen default permissions of internal system objects (e.g., Symbolic Links)" to "Enabled".
Rating Info
DISA Cat III. NIST impact 2.
Expert Comment
None
WN16-00-000310: A host-based firewall must be installed and enabled on the system.
Determine if a host-based firewall is installed and enabled on the system. If a host-based firewall is not installed and enabled on the system, this is a finding. The configuration requirements will be determined by the applicable firewall STIG.
Discussion
A firewall provides a line of defense against attack, allowing or blocking inbound and outbound connections based on a set of rules.
Fix
Install and enable a host-based firewall on the system.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000150: The required legal notice must be configured to display before console logon.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ Value Name: LegalNoticeText Value Type: REG_SZ Value: See message text below You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.
Discussion
Failure to display the logon banner prior to a logon attempt will negate legal proceedings resulting from unauthorized access to system resources. Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000024-GPOS-00007, SRG-OS-000228-GPOS-00088
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Interactive Logon: Message text for users attempting to log on" to the following: You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000330: Domain controllers must be configured to allow reset of machine account passwords.
This applies to domain controllers. It is NA for other systems. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\Netlogon\Parameters\ Value Name: RefusePasswordChange Value Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Enabling this setting on all domain controllers in a domain prevents domain members from changing their computer account passwords. If these passwords are weak or compromised, the inability to change them may leave these computers vulnerable.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Domain controller: Refuse machine account password changes" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-MS-000120: Windows Server 2016 must be running Credential Guard on domain-joined member servers.
For domain controllers and standalone or nondomain-joined systems, this is NA. Open "PowerShell" with elevated privileges (run as administrator). Enter the following: "Get-CimInstance -ClassName Win32_DeviceGuard -Namespace root\Microsoft\Windows\DeviceGuard" If "SecurityServicesRunning" does not include a value of "1" (e.g., "{1, 2}"), this is a finding. Alternately: Run "System Information". Under "System Summary", verify the following: If "Device Guard Security Services Running" does not list "Credential Guard", this is a finding. The policy settings referenced in the Fix section will configure the following registry value. However, due to hardware requirements, the registry value alone does not ensure proper function. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\DeviceGuard\ Value Name: LsaCfgFlags Value Type: REG_DWORD Value: 0x00000001 (1) (Enabled with UEFI lock) A Microsoft article on Credential Guard system requirement can be found at the following link: https://docs.microsoft.com/en-us/windows/security/identity-protection/credential-guard/credential-guard-requirements
Discussion
Credential Guard uses virtualization-based security to protect data that could be used in credential theft attacks if compromised. This authentication information, which was stored in the Local Security Authority (LSA) in previous versions of Windows, is isolated from the rest of the operating system and can only be accessed by privileged system software.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> System >> Device Guard >> "Turn On Virtualization Based Security" to "Enabled" with "Enabled with UEFI lock" selected for "Credential Guard Configuration". A Microsoft article on Credential Guard system requirement can be found at the following link: https://docs.microsoft.com/en-us/windows/security/identity-protection/credential-guard/credential-guard-requirements Severity Override Guidance: The AO can allow the severity override if they have reviewed the overall protection provided to the affected servers that are not capable of complying with the Credential Guard requirement. Items that should be reviewed/considered for compliance or mitigation for non-Credential Guard compliance are: The use of Microsoft Local Administrator Password Solution (LAPS) or similar products to control different local administrative passwords for all affected affected servers. This is to include a strict password change requirement (60 days or less). …. Strict separation of roles and duties. Server administrator credentials cannot be used on Windows 10 desktop to administer it. Documentation of all exceptions should be supplied. …. Use of a Privileged Access Workstation (PAW) and adherence to the Clean Source principle for administering affected affected servers. …. Boundary Protection that is currently in place to protect from vulnerabilities in the network/servers. …. Windows Defender rule block credential stealing from LSASS.exe is applied. This rule can only be applied if Windows Defender is in use. …. The overall number of vulnerabilities that are unmitigated on the network/servers.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-AU-000410: Windows Server 2016 must be configured to audit System - Security State Change successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. System >> Security State Change - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Security State Change records events related to changes in the security state, such as startup and shutdown of the system. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> System >> "Audit Security State Change" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000200: The Active Directory Domain Controllers Organizational Unit (OU) object must be configured with proper audit settings.
This applies to domain controllers. It is NA for other systems. Review the auditing configuration for the Domain Controller OU object. Open "Active Directory Users and Computers" (available from various menus or run "dsa.msc"). Ensure "Advanced Features" is selected in the "View" menu. Select the "Domain Controllers OU" under the domain being reviewed in the left pane. Right-click the "Domain Controllers OU" object and select "Properties". Select the "Security" tab. Select the "Advanced" button and then the "Auditing" tab. If the audit settings on the Domain Controllers OU object are not at least as inclusive as those below, this is a finding. Type - Fail Principal - Everyone Access - Full Control Inherited from - None Applies to - This object and all descendant objects The success types listed below are defaults. Where Special is listed in the summary screens for Access, detailed Permissions are provided for reference. Various Properties selections may also exist by default. Type - Success Principal - Everyone Access - Special Inherited from - None Applies to - This object only (Access - Special = Permissions: all create, delete and modify permissions) Type - Success Principal - Everyone Access - Write all properties Inherited from - None Applies to - This object and all descendant objects Two instances with the following summary information will be listed. Type - Success Principal - Everyone Access - (blank) Inherited from - (CN of domain) Applies to - Descendant Organizational Unit objects
Discussion
When inappropriate audit settings are configured for directory service database objects, it may be possible for a user or process to update the data without generating any tracking data. The impact of missing audit data is related to the type of object. A failure to capture audit data for objects used by identification, authentication, or authorization functions could degrade or eliminate the ability to track changes to access policy for systems or data. For Active Directory (AD), there are a number of critical object types in the domain naming context of the AD database for which auditing is essential. This includes the Domain Controller OU object. Because changes to these objects can significantly impact access controls or the availability of systems, the absence of auditing data makes it impossible to identify the source of changes that impact the confidentiality, integrity, and availability of data and systems throughout an AD domain. The lack of proper auditing can result in insufficient forensic evidence needed to investigate an incident and prosecute the intruder. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Open "Active Directory Users and Computers" (available from various menus or run "dsa.msc"). Ensure "Advanced Features" is selected in the "View" menu. Select the "Domain Controllers OU" under the domain being reviewed in the left pane. Right-click the "Domain Controllers OU" object and select "Properties". Select the "Security" tab. Select the "Advanced" button and then the "Auditing" tab. Configure the audit settings for Domain Controllers OU object to include the following. Type - Fail Principal - Everyone Access - Full Control Inherited from - None The success types listed below are defaults. Where Special is listed in the summary screens for Access, detailed Permissions are provided for reference. Various Properties selections may also exist by default. Type - Success Principal - Everyone Access - Special Inherited from - None Applies to - This object only (Access - Special = Permissions: all create, delete and modify permissions) Type - Success Principal - Everyone Access - Write all properties Inherited from - None Applies to - This object and all descendant objects Two instances with the following summary information will be listed. Type - Success Principal - Everyone Access - (blank) Inherited from - (CN of domain) Applies to - Descendant Organizational Unit objects
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000250: AutoPlay must be turned off for non-volume devices.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\Explorer\ Value Name: NoAutoplayfornonVolume Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Allowing AutoPlay to execute may introduce malicious code to a system. AutoPlay begins reading from a drive as soon as media is inserted into the drive. As a result, the setup file of programs or music on audio media may start. This setting will disable AutoPlay for non-volume devices, such as Media Transfer Protocol (MTP) devices.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> AutoPlay Policies >> "Disallow Autoplay for non-volume devices" to "Enabled".
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-AU-000370: Windows Server 2016 must be configured to audit System - IPsec Driver successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. System >> IPsec Driver - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. IPsec Driver records events related to the IPsec Driver, such as dropped packets. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> System >> "Audit IPsec Driver" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000170: Active Directory Group Policy objects must be configured with proper audit settings.
This applies to domain controllers. It is NA for other systems. Review the auditing configuration for all Group Policy objects. Open "Group Policy Management" (available from various menus or run "gpmc.msc"). Navigate to "Group Policy Objects" in the domain being reviewed (Forest >> Domains >> Domain). For each Group Policy object: Select the Group Policy object item in the left pane. Select the "Delegation" tab in the right pane. Select the "Advanced" button. Select the "Advanced" button again and then the "Auditing" tab. If the audit settings for any Group Policy object are not at least as inclusive as those below, this is a finding. Type - Fail Principal - Everyone Access - Full Control Applies to - This object and all descendant objects or Descendant groupPolicyContainer objects The three Success types listed below are defaults inherited from the Parent Object. Where Special is listed in the summary screens for Access, detailed Permissions are provided for reference. Type - Success Principal - Everyone Access - Special (Permissions: Write all properties, Modify permissions; Properties: all "Write" type selected) Inherited from - Parent Object Applies to - Descendant groupPolicyContainer objects Two instances with the following summary information will be listed. Type - Success Principal - Everyone Access - blank (Permissions: none selected; Properties: one instance - Write gPLink, one instance - Write gPOptions) Inherited from - Parent Object Applies to - Descendant Organization Unit Objects
Discussion
When inappropriate audit settings are configured for directory service database objects, it may be possible for a user or process to update the data without generating any tracking data. The impact of missing audit data is related to the type of object. A failure to capture audit data for objects used by identification, authentication, or authorization functions could degrade or eliminate the ability to track changes to access policy for systems or data. For Active Directory (AD), there are a number of critical object types in the domain naming context of the AD database for which auditing is essential. This includes Group Policy objects. Because changes to these objects can significantly impact access controls or the availability of systems, the absence of auditing data makes it impossible to identify the source of changes that impact the confidentiality, integrity, and availability of data and systems throughout an AD domain. The lack of proper auditing can result in insufficient forensic evidence needed to investigate an incident and prosecute the intruder. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Configure the audit settings for Group Policy objects to include the following. This can be done at the Policy level in Active Directory to apply to all group policies. Open "Active Directory Users and Computers" (available from various menus or run "dsa.msc"). Select "Advanced Features" from the "View" Menu. Navigate to [Domain] >> System >> Policies in the left panel. Right click "Policies", select "Properties". Select the "Security" tab. Select the "Advanced" button. Select the "Auditing" tab. Type - Fail Principal - Everyone Access - Full Control Applies to - This object and all descendant objects or Descendant groupPolicyContainer objects The three Success types listed below are defaults inherited from the Parent Object. Where Special is listed in the summary screens for Access, detailed Permissions are provided for reference. Type - Success Principal - Everyone Access - Special (Permissions: Write all properties, Modify permissions; Properties: all "Write" type selected) Inherited from - Parent Object Applies to - Descendant groupPolicyContainer objects Two instances with the following summary information will be listed. Type - Success Principal - Everyone Access - blank (Permissions: none selected; Properties: one instance - Write gPLink, one instance - Write gPOptions) Inherited from - Parent Object Applies to - Descendant Organization Unit Objects
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000420: The Enable computer and user accounts to be trusted for delegation user right must only be assigned to the Administrators group on domain controllers.
This applies to domain controllers. A separate version applies to other systems. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Enable computer and user accounts to be trusted for delegation" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeEnableDelegationPrivilege" user right, this is a finding. S-1-5-32-544 (Administrators)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Enable computer and user accounts to be trusted for delegation" user right allows the "Trusted for Delegation" setting to be changed. This could allow unauthorized users to impersonate other users.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Enable computer and user accounts to be trusted for delegation" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000470: Secure Boot must be enabled on Windows Server 2016 systems.
Some older systems may not have UEFI firmware. This is currently a CAT III; it will be raised in severity at a future date when broad support of Windows hardware and firmware requirements are expected to be met. Devices that have UEFI firmware must have Secure Boot enabled. Run "System Information". Under "System Summary", if "Secure Boot State" does not display "On", this is a finding.
Discussion
Secure Boot is a standard that ensures systems boot only to a trusted operating system. Secure Boot is required to support additional security features in Windows Server 2016, including Virtualization Based Security and Credential Guard. If Secure Boot is turned off, these security features will not function.
Fix
Enable Secure Boot in the system firmware.
Rating Info
DISA Cat III. NIST impact 2.
Expert Comment
None
WN16-00-000430: FTP servers must be configured to prevent anonymous logons.
If FTP is not installed on the system, this is NA. Open "Internet Information Services (IIS) Manager". Select the server. Double-click "FTP Authentication". If the "Anonymous Authentication" status is "Enabled", this is a finding.
Discussion
The FTP service allows remote users to access shared files and directories. Allowing anonymous FTP connections makes user auditing difficult. Using accounts that have administrator privileges to log on to FTP risks that the userid and password will be captured on the network and give administrator access to an unauthorized user.
Fix
Configure the FTP service to prevent anonymous logons. Open "Internet Information Services (IIS) Manager". Select the server. Double-click "FTP Authentication". Select "Anonymous Authentication". Select "Disabled" under "Actions".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000510: User Account Control must only elevate UIAccess applications that are installed in secure locations.
UAC requirements are NA for Server Core installations (this is the default installation option for Windows Server 2016 versus Server with Desktop Experience) as well as Nano Server. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ Value Name: EnableSecureUIAPaths Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
User Account Control (UAC) is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting configures Windows to only allow applications installed in a secure location on the file system, such as the Program Files or the Windows\System32 folders, to run with elevated privileges.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "User Account Control: Only elevate UIAccess applications that are installed in secure locations" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AC-000080: Windows Server 2016 must have the built-in Windows password complexity policy enabled.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Password Policy. If the value for "Password must meet complexity requirements" is not set to "Enabled", this is a finding. For server core installations, run the following command: Secedit /Export /Areas SecurityPolicy /CFG C:\Path\FileName.Txt If "PasswordComplexity" equals "0" in the file, this is a finding. Note: If an external password filter is in use that enforces all four character types and requires this setting to be set to "Disabled", this would not be considered a finding. If this setting does not affect the use of an external password filter, it must be enabled for fallback purposes.
Discussion
The use of complex passwords increases their strength against attack. The built-in Windows password complexity policy requires passwords to contain at least three of the four types of characters (numbers, upper- and lower-case letters, and special characters) and prevents the inclusion of user names or parts of user names. Satisfies: SRG-OS-000069-GPOS-00037, SRG-OS-000070-GPOS-00038, SRG-OS-000071-GPOS-00039, SRG-OS-000266-GPOS-00101
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Password Policy >> "Password must meet complexity requirements" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-PK-000020: The DoD Interoperability Root CA cross-certificates must be installed in the Untrusted Certificates Store on unclassified systems.
Verify the DoD Interoperability cross-certificates are installed on unclassified systems as Untrusted Certificates. Run "PowerShell" as an administrator. Execute the following command: Get-ChildItem -Path Cert:Localmachine\disallowed | Where {$_.Issuer -Like "*DoD Interoperability*" -and $_.Subject -Like "*DoD*"} | FL Subject, Issuer, Thumbprint, NotAfter If the following certificate "Subject", "Issuer", and "Thumbprint" information is not displayed, this is a finding. Subject: CN=DoD Root CA 3, OU=PKI, OU=DoD, O=U.S. Government, C=US Issuer: CN=DoD Interoperability Root CA 2, OU=PKI, OU=DoD, O=U.S. Government, C=US Thumbprint: 49CBE933151872E17C8EAE7F0ABA97FB610F6477 NotAfter: 11/16/2024 9:57:16 AM Alternately use the Certificates MMC snap-in: Run "MMC". Select "File", "Add/Remove Snap-in". Select "Certificates", click "Add". Select "Computer account", click "Next". Select "Local computer: (the computer this console is running on)", click "Finish". Click "OK". Expand "Certificates" and navigate to Untrusted Certificates >> Certificates. For each certificate with "DoD Root CA…" under "Issued To" and "DoD Interoperability Root CA…" under "Issued By": Right-click on the certificate and select "Open". Select the "Details" tab. Scroll to the bottom and select "Thumbprint". If the certificates below are not listed or the value for the "Thumbprint" field is not as noted, this is a finding. If an expired certificate ("Valid to" date) is not listed in the results, this is not a finding. Subject: CN=DoD Root CA 3, OU=PKI, OU=DoD, O=U.S. Government, C=US Issuer: CN=DoD Interoperability Root CA 2, OU=PKI, OU=DoD, O=U.S. Government, C=US Thumbprint: 49CBE933151872E17C8EAE7F0ABA97FB610F6477 NotAfter: 11/16/2024 9:57:16 AM
Discussion
To ensure users do not experience denial of service when performing certificate-based authentication to DoD websites due to the system chaining to a root other than DoD Root CAs, the DoD Interoperability Root CA cross-certificates must be installed in the Untrusted Certificate Store. This requirement only applies to unclassified systems. Satisfies: SRG-OS-000066-GPOS-00034, SRG-OS-000403-GPOS-00182
Fix
Install the DoD Interoperability Root CA cross-certificates on unclassified systems. Issued To - Issued By - Thumbprint DoD Root CA 3 - DoD Interoperability Root CA 2 - 49CBE933151872E17C8EAE7F0ABA97FB610F6477 The certificates can be installed using the InstallRoot tool. The tool and user guide are available on Cyber Exchange at https://cyber.mil/pki-pke/tools-configuration-files. Certificate bundles published by the PKI can be found at https://crl.gds.disa.mil/.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000050: The Kerberos policy user ticket renewal maximum lifetime must be limited to seven days or less.
This applies to domain controllers. It is NA for other systems. Verify the following is configured in the Default Domain Policy. Open "Group Policy Management". Navigate to "Group Policy Objects" in the Domain being reviewed (Forest >> Domains >> Domain). Right-click on the "Default Domain Policy". Select "Edit". Navigate to Computer Configuration >> Policies >> Windows Settings >> Security Settings >> Account Policies >> Kerberos Policy. If the "Maximum lifetime for user ticket renewal" is greater than "7" days, this is a finding.
Discussion
This setting determines the period of time (in days) during which a user's Ticket Granting Ticket (TGT) may be renewed. This security configuration limits the amount of time an attacker has to crack the TGT and gain access. Satisfies: SRG-OS-000112-GPOS-00057, SRG-OS-000113-GPOS-00058
Fix
Configure the policy value in the Default Domain Policy for Computer Configuration >> Policies >> Windows Settings >> Security Settings >> Account Policies >> Kerberos Policy >> "Maximum lifetime for user ticket renewal" to a maximum of "7" days or less.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000280: Windows Server 2016 must be configured to audit Logon/Logoff - Special Logon successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Logon/Logoff >> Special Logon - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Special Logon records special logons that have administrative privileges and can be used to elevate processes. Satisfies: SRG-OS-000470-GPOS-00214, SRG-OS-000472-GPOS-00217, SRG-OS-000473-GPOS-00218, SRG-OS-000475-GPOS-00220
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Logon/Logoff >> "Audit Special Logon" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AC-000010: Windows 2016 account lockout duration must be configured to 15 minutes or greater.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Account Lockout Policy. If the "Account lockout duration" is less than "15" minutes (excluding "0"), this is a finding. For server core installations, run the following command: Secedit /Export /Areas SecurityPolicy /CFG C:\Path\FileName.Txt If "LockoutDuration" is less than "15" (excluding "0") in the file, this is a finding. Configuring this to "0", requiring an administrator to unlock the account, is more restrictive and is not a finding.
Discussion
The account lockout feature, when enabled, prevents brute-force password attacks on the system. This parameter specifies the period of time that an account will remain locked after the specified number of failed logon attempts.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Account Lockout Policy >> "Account lockout duration" to "15" minutes or greater. A value of "0" is also acceptable, requiring an administrator to unlock the account.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000140: The machine inactivity limit must be set to 15 minutes, locking the system with the screen saver.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ Value Name: InactivityTimeoutSecs Value Type: REG_DWORD Value: 0x00000384 (900) (or less, excluding "0" which is effectively disabled)
Discussion
Unattended systems are susceptible to unauthorized use and should be locked when unattended. The screen saver should be set at a maximum of 15 minutes and be password protected. This protects critical and sensitive data from exposure to unauthorized personnel with physical access to the computer.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Interactive logon: Machine inactivity limit" to "900" seconds or less, excluding "0" which is effectively disabled.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000330: Windows Server 2016 Windows SmartScreen must be enabled.
This is applicable to unclassified systems; for other systems, this is NA. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\System\ Value Name: EnableSmartScreen Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Windows SmartScreen helps protect systems from programs downloaded from the internet that may be malicious. Enabling SmartScreen will warn users of potentially malicious programs.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> File Explorer >> "Configure Windows SmartScreen" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000400: Windows Server 2016 must be configured to audit System - Other System Events failures.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. System >> Other System Events - Failure
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Audit Other System Events records information related to cryptographic key operations and the Windows Firewall service. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> System >> "Audit Other System Events" with "Failure" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000060: Manually managed application account passwords must be at least 14 characters in length.
Determine if manually managed application/service accounts exist. If none exist, this is NA. Verify the organization has a policy to ensure passwords for manually managed application/service accounts are at least 14 characters in length. If such a policy does not exist or has not been implemented, this is a finding.
Discussion
Application/service account passwords must be of sufficient length to prevent being easily cracked. Application/service accounts that are manually managed must have passwords at least 14 characters in length.
Fix
Establish a policy that requires application/service account passwords that are manually managed to be at least 14 characters in length. Ensure the policy is enforced.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000220: The Impersonate a client after authentication user right must only be assigned to Administrators, Service, Local Service, and Network Service.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Impersonate a client after authentication" user right, this is a finding. - Administrators - Service - Local Service - Network Service For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeImpersonatePrivilege" user right, this is a finding. S-1-5-32-544 (Administrators) S-1-5-6 (Service) S-1-5-19 (Local Service) S-1-5-20 (Network Service) If an application requires this user right, this would not be a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070).
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Impersonate a client after authentication" user right allows a program to impersonate another user or account to run on their behalf. An attacker could use this to elevate privileges.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Impersonate a client after authentication" to include only the following accounts or groups: - Administrators - Service - Local Service - Network Service
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000390: Windows Server 2016 must be configured to at least negotiate signing for LDAP client signing.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\LDAP\ Value Name: LDAPClientIntegrity Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
This setting controls the signing requirements for LDAP clients. This must be set to "Negotiate signing" or "Require signing", depending on the environment and type of LDAP server in use.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network security: LDAP client signing requirements" to "Negotiate signing" at a minimum.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000500: The Windows Remote Management (WinRM) client must not use Basic authentication.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\WinRM\Client\ Value Name: AllowBasic Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Basic authentication uses plain-text passwords that could be used to compromise a system. Disabling Basic authentication will reduce this potential.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Windows Remote Management (WinRM) >> WinRM Client >> "Allow Basic authentication" to "Disabled".
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-SO-000120: The maximum age for machine account passwords must be configured to 30 days or less.
This is the default configuration for this setting (30 days). If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\Netlogon\Parameters\ Value Name: MaximumPasswordAge Value Type: REG_DWORD Value: 0x0000001e (30) (or less, but not 0)
Discussion
Computer account passwords are changed automatically on a regular basis. This setting controls the maximum password age that a machine account may have. This must be set to no more than 30 days, ensuring the machine changes its password monthly.
Fix
This is the default configuration for this setting (30 days). Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Domain member: Maximum machine account password age" to "30" or less (excluding "0", which is unacceptable).
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000460: User Account Control approval mode for the built-in Administrator must be enabled.
UAC requirements are NA for Server Core installations (this is the default installation option for Windows Server 2016 versus Server with Desktop Experience) as well as Nano Server. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ Value Name: FilterAdministratorToken Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
User Account Control (UAC) is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting configures the built-in Administrator account so that it runs in Admin Approval Mode. Satisfies: SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00156
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "User Account Control: Admin Approval Mode for the Built-in Administrator account" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000150: Local volumes must use a format that supports NTFS attributes.
Open "Computer Management". Select "Disk Management" under "Storage". For each local volume, if the file system does not indicate "NTFS", this is a finding. "ReFS" (resilient file system) is also acceptable and would not be a finding. This does not apply to system partitions such the Recovery and EFI System Partition.
Discussion
The ability to set access permissions and auditing is critical to maintaining the security and proper access controls of a system. To support this, volumes must be formatted using a file system that supports NTFS attributes.
Fix
Format volumes to use NTFS or ReFS.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-CC-000280: Administrator accounts must not be enumerated during elevation.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\CredUI\ Value Name: EnumerateAdministrators Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Enumeration of administrator accounts when elevating can provide part of the logon information to an unauthorized user. This setting configures the system to always require users to type in a username and password to elevate a running application.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Credential User Interface >> "Enumerate administrator accounts on elevation" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000190: The setting Microsoft network client: Digitally sign communications (always) must be configured to Enabled.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters\ Value Name: RequireSecuritySignature Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
The server message block (SMB) protocol provides the basis for many network operations. Digitally signed SMB packets aid in preventing man-in-the-middle attacks. If this policy is enabled, the SMB client will only communicate with an SMB server that performs SMB packet signing. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Microsoft network client: Digitally sign communications (always)" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000421: The Windows Explorer Preview pane must be disabled for Windows Server 2016.
If the following registry values do not exist or are not configured as specified, this is a finding: Registry Hive: HKEY_CURRENT_USER Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer Value Name: NoPreviewPane Value Type: REG_DWORD Value: 1 Registry Hive: HKEY_CURRENT_USER Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer Value Name: NoReadingPane Value Type: REG_DWORD Value: 1
Discussion
A known vulnerability in Windows could allow the execution of malicious code by either opening a compromised document or viewing it in the Windows Preview pane. Organizations must disable the Windows Preview pane and Windows Detail pane.
Fix
Ensure the following settings are configured for Windows Server 2016 locally or applied through group policy. Configure the policy value for User Configuration >> Administrative Templates >> Windows Components >> File Explorer >> Explorer Frame Pane "Turn off Preview Pane" to "Enabled". Configure the policy value for User Configuration >> Administrative Templates >> Windows Components >> File Explorer >> Explorer Frame Pane "Turn on or off details pane" to "Enabled" and "Configure details pane" to "Always hide".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000130: The Debug programs user right must only be assigned to the Administrators group.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Debug programs" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeDebugPrivilege" user right, this is a finding. S-1-5-32-544 (Administrators) If an application requires this user right, this would not be a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070). Passwords for application accounts with this user right must be protected as highly privileged accounts.
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Debug programs" user right can attach a debugger to any process or to the kernel, providing complete access to sensitive and critical operating system components. This right is given to Administrators in the default configuration.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Debug programs" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-UR-000090: The Create a token object user right must not be assigned to any groups or accounts.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups are granted the "Create a token object" user right, this is a finding. If an application requires this user right, this would not be a finding. For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs are granted the "SeCreateTokenPrivilege" user right, this is a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070). Passwords for application accounts with this user right must be protected as highly privileged accounts.
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Create a token object" user right allows a process to create an access token. This could be used to provide elevated rights and compromise a system.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Create a token object" to be defined but containing no entries (blank).
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-AU-000140: Windows Server 2016 must be configured to audit Account Management - User Account Management successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Account Management >> User Account Management - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. User Account Management records events such as creating, changing, deleting, renaming, disabling, or enabling user accounts. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000476-GPOS-00221
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Account Management >> "Audit User Account Management" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000170: Printing over HTTP must be prevented.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows NT\Printers\ Value Name: DisableHTTPPrinting Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Some features may communicate with the vendor, sending system information or downloading data or components for the feature. Turning off this capability will prevent potentially sensitive information from being sent outside the enterprise and will prevent uncontrolled updates to the system. This setting prevents the client computer from printing over HTTP, which allows the computer to print to printers on the intranet as well as the Internet.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> System >> Internet Communication Management >> Internet Communication settings >> "Turn off printing over HTTP" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000250: Windows Server 2016 must be configured to audit Logon/Logoff - Logoff successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Logon/Logoff >> Logoff - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Logoff records user logoffs. If this is an interactive logoff, it is recorded on the local system. If it is to a network share, it is recorded on the system accessed. Satisfies: SRG-OS-000032-GPOS-00013, SRG-OS-000470-GPOS-00214, SRG-OS-000472-GPOS-00217, SRG-OS-000473-GPOS-00218, SRG-OS-000475-GPOS-00220
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Logon/Logoff >> "Audit Logoff" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000100: The setting Domain member: Digitally sign secure channel data (when possible) must be configured to Enabled.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\Netlogon\Parameters\ Value Name: SignSecureChannel Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Requests sent on the secure channel are authenticated, and sensitive information (such as passwords) is encrypted, but the channel is not integrity checked. If this policy is enabled, outgoing secure channel traffic will be signed. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Domain member: Digitally sign secure channel data (when possible)" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000280: The Perform volume maintenance tasks user right must only be assigned to the Administrators group.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If an application requires this user right, this is not a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeManageVolumePrivilege" user right, this is a finding. S-1-5-32-544 (Administrators)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Perform volume maintenance tasks" user right can manage volume and disk configurations. This could be used to delete volumes, resulting in data loss or a denial of service.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> Perform volume maintenance tasks to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000060: Windows Server 2016 must be configured to prevent Internet Control Message Protocol (ICMP) redirects from overriding Open Shortest Path First (OSPF)-generated routes.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\ Value Name: EnableICMPRedirect Value Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Allowing ICMP redirect of routes can lead to traffic not being routed properly. When disabled, this forces ICMP to be routed via the shortest path first.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> MSS (Legacy) >> "MSS: (EnableICMPRedirect) Allow ICMP redirects to override OSPF generated routes" to "Disabled". This policy setting requires the installation of the MSS-Legacy custom templates included with the STIG package. "MSS-Legacy.admx" and "MSS-Legacy.adml" must be copied to the \Windows\PolicyDefinitions and \Windows\PolicyDefinitions\en-US directories respectively.
Rating Info
DISA Cat III. NIST impact 2.
Expert Comment
None
WN16-SO-000490: User Account Control must automatically deny standard user requests for elevation.
UAC requirements are NA for Server Core installations (this is the default installation option for Windows Server 2016 versus Server with Desktop Experience) as well as Nano Server. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ Value Name: ConsentPromptBehaviorUser Value Type: REG_DWORD Value: 0x00000000 (0)
Discussion
User Account Control (UAC) is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting controls the behavior of elevation when requested by a standard user account. Satisfies: SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00156
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "User Account Control: Behavior of the elevation prompt for standard users" to "Automatically deny elevation requests".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000150: Group Policy objects must be reprocessed even if they have not changed.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\Group Policy\{35378EAC-683F-11D2-A89A-00C04FBBCFA2}\ Value Name: NoGPOListChanges Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Registry entries for group policy settings can potentially be changed from the required configuration. This could occur as part of troubleshooting or by a malicious process on a compromised system. Enabling this setting and then selecting the "Process even if the Group Policy objects have not changed" option ensures the policies will be reprocessed even if none have been changed. This way, any unauthorized changes are forced to match the domain-based group policy settings again.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> System >> Group Policy >> "Configure registry policy processing" to "Enabled" with the option "Process even if the Group Policy objects have not changed" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000080: Shared user accounts must not be permitted on the system.
Determine whether any shared accounts exist. If no shared accounts exist, this is NA. Shared accounts, such as required by an application, may be approved by the organization. This must be documented with the ISSO. Documentation must include the reason for the account, who has access to the account, and how the risk of using the shared account is mitigated to include monitoring account activity. If unapproved shared accounts exist, this is a finding.
Discussion
Shared accounts (accounts where two or more people log on with the same user identification) do not provide adequate identification and authentication. There is no way to provide for nonrepudiation or individual accountability for system access and resource usage.
Fix
Remove unapproved shared accounts from the system. Document required shared accounts with the ISSO. Documentation must include the reason for the account, who has access to the account, and how the risk of using the shared account is mitigated to include monitoring account activity.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000200: The Force shutdown from a remote system user right must only be assigned to the Administrators group.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Force shutdown from a remote system" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeRemoteShutdownPrivilege" user right, this is a finding. S-1-5-32-544 (Administrators)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Force shutdown from a remote system" user right can remotely shut down a system, which could result in a denial of service.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Force shutdown from a remote system" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000240: Windows Server 2016 must be configured to audit Logon/Logoff - Group Membership successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*" Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Logon/Logoff >> Group Membership - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Audit Group Membership records information related to the group membership of a user's logon token.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Logon/Logoff >> "Audit Group Membership" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-MS-000410: The "Deny log on through Remote Desktop Services" user right on member servers must be configured to prevent access from highly privileged domain accounts and all local accounts on domain systems and from unauthenticated access on all systems.
This applies to member servers and standalone or nondomain-joined systems. A separate version applies to domain controllers. Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If the following accounts or groups are not defined for the "Deny log on through Remote Desktop Services" user right, this is a finding. Domain Systems Only: - Enterprise Admins group - Domain Admins group - Local account (see Note below) All Systems: - Guests group For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If the following SIDs are not defined for the "SeDenyRemoteInteractiveLogonRight" user right, this is a finding. Domain Systems Only: S-1-5-root domain-519 (Enterprise Admins) S-1-5-domain-512 (Domain Admins) S-1-5-113 ("Local account") All Systems: S-1-5-32-546 (Guests) Note: "Local account" is referring to the Windows built-in security group.
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. The "Deny log on through Remote Desktop Services" user right defines the accounts that are prevented from logging on using Remote Desktop Services. In an Active Directory Domain, denying logons to the Enterprise Admins and Domain Admins groups on lower-trust systems helps mitigate the risk of privilege escalation from credential theft attacks, which could lead to the compromise of an entire domain. Local accounts on domain-joined systems must also be assigned this right to decrease the risk of lateral movement resulting from credential theft attacks. The Guests group must be assigned this right to prevent unauthenticated access.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Deny log on through Remote Desktop Services" to include the following: Domain Systems Only: - Enterprise Admins group - Domain Admins group - Local account (see Note below) All Systems: - Guests group Note: "Local account" is referring to the Windows built-in security group.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000030: Permissions for the Application event log must prevent access by non-privileged accounts.
Navigate to the Application event log file. The default location is the "%SystemRoot%\System32\winevt\Logs" folder. However, the logs may have been moved to another folder. If the permissions for the "Application.evtx" file are not as restrictive as the default permissions listed below, this is a finding. Eventlog - Full Control SYSTEM - Full Control Administrators - Full Control
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. The Application event log may be susceptible to tampering if proper permissions are not applied. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029
Fix
Configure the permissions on the Application event log file (Application.evtx) to prevent access by non-privileged accounts. The default permissions listed below satisfy this requirement: Eventlog - Full Control SYSTEM - Full Control Administrators - Full Control The default location is the "%SystemRoot%\ System32\winevt\Logs" folder. If the location of the logs has been changed, when adding Eventlog to the permissions, it must be entered as "NT Service\Eventlog".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000480: User Account Control must, at a minimum, prompt administrators for consent on the secure desktop.
UAC requirements are NA for Server Core installations (this is default installation option for Windows Server 2016 versus Server with Desktop Experience) as well as Nano Server. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ Value Name: ConsentPromptBehaviorAdmin Value Type: REG_DWORD Value: 0x00000002 (2) (Prompt for consent on the secure desktop) 0x00000001 (1) (Prompt for credentials on the secure desktop)
Discussion
User Account Control (UAC) is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting configures the elevation requirements for logged-on administrators to complete a task that requires raised privileges.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "User Account Control: Behavior of the elevation prompt for administrators in Admin Approval Mode" to "Prompt for consent on the secure desktop". The more secure option for this setting, "Prompt for credentials on the secure desktop", would also be acceptable.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000030: Passwords for the built-in Administrator account must be changed at least every 60 days.
Review the password last set date for the built-in Administrator account. Domain controllers: Open "PowerShell". Enter "Get-ADUser -Filter * -Properties SID, PasswordLastSet | Where SID -Like "*-500" | Ft Name, SID, PasswordLastSet". If the "PasswordLastSet" date is greater than "60" days old, this is a finding. Member servers and standalone or nondomain-joined systems: Open "Command Prompt". Enter 'Net User [account name] | Find /i "Password Last Set"', where [account name] is the name of the built-in administrator account. (The name of the built-in Administrator account must be changed to something other than "Administrator" per STIG requirements.) If the "PasswordLastSet" date is greater than "60" days old, this is a finding.
Discussion
The longer a password is in use, the greater the opportunity for someone to gain unauthorized knowledge of the password. The built-in Administrator account is not generally used and its password not may be changed as frequently as necessary. Changing the password for the built-in Administrator account on a regular basis will limit its exposure. It is highly recommended to use Microsoft's Local Administrator Password Solution (LAPS). Domain-joined systems can configure this to occur more frequently. LAPS will change the password every "30" days by default. The AO still has the overall authority to use another equivalent capability to accomplish the check.
Fix
Change the built-in Administrator account password at least every "60" days. It is highly recommended to use Microsoft's LAPS, which may be used on domain-joined member servers to accomplish this. The AO still has the overall authority to use another equivalent capability to accomplish the check.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000540: The Windows Remote Management (WinRM) service must not allow unencrypted traffic.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\WinRM\Service\ Value Name: AllowUnencryptedTraffic Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Unencrypted remote access to a system can allow sensitive information to be compromised. Windows remote management connections must be encrypted to prevent this. Satisfies: SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Windows Remote Management (WinRM) >> WinRM Service >> "Allow unencrypted traffic" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000470: Users must be notified if a web-based program attempts to install software.
The default behavior is for Internet Explorer to warn users and select whether to allow or refuse installation when a web-based program attempts to install software on the system. If the registry value name below does not exist, this is not a finding. If it exists and is configured with a value of "0", this is not a finding. If it exists and is configured with a value of "1", this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\Installer\ Value Name: SafeForScripting Value Type: REG_DWORD Value: 0x00000000 (0) (or if the Value Name does not exist)
Discussion
Web-based programs may attempt to install malicious software on a system. Ensuring users are notified if a web-based program attempts to install software allows them to refuse the installation.
Fix
The default behavior is for Internet Explorer to warn users and select whether to allow or refuse installation when a web-based program attempts to install software on the system. If this needs to be corrected, configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Windows Installer >> "Prevent Internet Explorer security prompt for Windows Installer scripts" to "Not Configured" or "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000110: Systems must be maintained at a supported servicing level.
Open "Command Prompt". Enter "winver.exe". If the "About Windows" dialog box does not display "Microsoft Windows Server Version 1607 (Build 14393.xxx)" or greater, this is a finding. Preview versions must not be used in a production environment.
Discussion
Systems at unsupported servicing levels will not receive security updates for new vulnerabilities, which leave them subject to exploitation. Systems must be maintained at a servicing level supported by the vendor with new security updates.
Fix
Update the system to a Version 1607 (Build 14393.xxx) or greater.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-SO-000080: The setting Domain member: Digitally encrypt or sign secure channel data (always) must be configured to Enabled.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\Netlogon\Parameters\ Value Name: RequireSignOrSeal Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Requests sent on the secure channel are authenticated, and sensitive information (such as passwords) is encrypted, but not all information is encrypted. If this policy is enabled, outgoing secure channel traffic will be encrypted and signed. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Domain member: Digitally encrypt or sign secure channel data (always)" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000040: Permissions for the Security event log must prevent access by non-privileged accounts.
Navigate to the Security event log file. The default location is the "%SystemRoot%\System32\winevt\Logs" folder. However, the logs may have been moved to another folder. If the permissions for the "Security.evtx" file are not as restrictive as the default permissions listed below, this is a finding. Eventlog - Full Control SYSTEM - Full Control Administrators - Full Control
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. The Security event log may disclose sensitive information or be susceptible to tampering if proper permissions are not applied. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029
Fix
Configure the permissions on the Security event log file (Security.evtx) to prevent access by non-privileged accounts. The default permissions listed below satisfy this requirement: Eventlog - Full Control SYSTEM - Full Control Administrators - Full Control The default location is the "%SystemRoot%\ System32\winevt\Logs" folder. If the location of the logs has been changed, when adding Eventlog to the permissions, it must be entered as "NT Service\Eventlog".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-MS-000020: Local administrator accounts must have their privileged token filtered to prevent elevated privileges from being used over the network on domain systems.
This applies to member servers. For domain controllers and standalone or nondomain-joined systems, this is NA. If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System Value Name: LocalAccountTokenFilterPolicy Type: REG_DWORD Value: 0x00000000 (0) This setting may cause issues with some network scanning tools if local administrative accounts are used remotely. Scans should use domain accounts where possible. If a local administrative account must be used, temporarily enabling the privileged token by configuring the registry value to "1" may be required.
Discussion
A compromised local administrator account can provide means for an attacker to move laterally between domain systems. With User Account Control enabled, filtering the privileged token for local administrator accounts will prevent the elevated privileges of these accounts from being used over the network.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> MS Security Guide >> "Apply UAC restrictions to local accounts on network logons" to "Enabled". This policy setting requires the installation of the SecGuide custom templates included with the STIG package. "SecGuide.admx" and "SecGuide.adml" must be copied to the \Windows\PolicyDefinitions and \Windows\PolicyDefinitions\en-US directories respectively.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000070: Windows Server 2016 must be configured to ignore NetBIOS name release requests except from WINS servers.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\Netbt\Parameters\ Value Name: NoNameReleaseOnDemand Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Configuring the system to ignore name release requests, except from WINS servers, prevents a denial of service (DoS) attack. The DoS consists of sending a NetBIOS name release request to the server for each entry in the server's cache, causing a response delay in the normal operation of the server's WINS resolution capability.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> MSS (Legacy) >> "MSS: (NoNameReleaseOnDemand) Allow the computer to ignore NetBIOS name release requests except from WINS servers" to "Enabled". This policy setting requires the installation of the MSS-Legacy custom templates included with the STIG package. "MSS-Legacy.admx" and "MSS-Legacy.adml" must be copied to the \Windows\PolicyDefinitions and \Windows\PolicyDefinitions\en-US directories respectively.
Rating Info
DISA Cat III. NIST impact 2.
Expert Comment
None
WN16-DC-000080: The Active Directory SYSVOL directory must have the proper access control permissions.
This applies to domain controllers. It is NA for other systems. Open a command prompt. Run "net share". Make note of the directory location of the SYSVOL share. By default, this will be \Windows\SYSVOL\sysvol. For this requirement, permissions will be verified at the first SYSVOL directory level. If any standard user accounts or groups have greater than "Read & execute" permissions, this is a finding. The default permissions noted below meet this requirement. Open "Command Prompt". Run "icacls c:\Windows\SYSVOL". The following results should be displayed: NT AUTHORITY\Authenticated Users:(RX) NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(GR,GE) BUILTIN\Server Operators:(RX) BUILTIN\Server Operators:(OI)(CI)(IO)(GR,GE) BUILTIN\Administrators:(M,WDAC,WO) BUILTIN\Administrators:(OI)(CI)(IO)(F) NT AUTHORITY\SYSTEM:(F) NT AUTHORITY\SYSTEM:(OI)(CI)(IO)(F) BUILTIN\Administrators:(M,WDAC,WO) CREATOR OWNER:(OI)(CI)(IO)(F) (RX) - Read & execute Run "icacls /help" to view definitions of other permission codes.
Discussion
Improper access permissions for directory data files could allow unauthorized users to read, modify, or delete directory data. The SYSVOL directory contains public files (to the domain) such as policies and logon scripts. Data in shared subdirectories are replicated to all domain controllers in a domain.
Fix
Maintain the permissions on the SYSVOL directory. Do not allow greater than "Read & execute" permissions for standard user accounts or groups. The defaults below meet this requirement. C:\Windows\SYSVOL Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to Authenticated Users - Read & execute - This folder, subfolder, and files Server Operators - Read & execute- This folder, subfolder, and files Administrators - Special - This folder only (Special = Basic Permissions: all selected except Full control) CREATOR OWNER - Full control - Subfolders and files only Administrators - Full control - Subfolders and files only SYSTEM - Full control - This folder, subfolders, and files
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-AU-000070: Windows Server 2016 must be configured to audit Account Logon - Credential Validation successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Account Logon >> Credential Validation - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Credential Validation records events related to validation tests on credentials for a user account logon.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Account Logon >> "Audit Credential Validation" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000140: Early Launch Antimalware, Boot-Start Driver Initialization Policy must prevent boot drivers identified as bad.
The default behavior is for Early Launch Antimalware - Boot-Start Driver Initialization policy to enforce "Good, unknown and bad but critical" (preventing "bad"). If the registry value name below does not exist, this is not a finding. If it exists and is configured with a value of "0x00000007 (7)", this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Policies\EarlyLaunch\ Value Name: DriverLoadPolicy Value Type: REG_DWORD Value: 0x00000001 (1), 0x00000003 (3), or 0x00000008 (8) (or if the Value Name does not exist) Possible values for this setting are: 8 - Good only 1 - Good and unknown 3 - Good, unknown and bad but critical 7 - All (which includes "bad" and would be a finding)
Discussion
Compromised boot drivers can introduce malware prior to protection mechanisms that load after initialization. The Early Launch Antimalware driver can limit allowed drivers based on classifications determined by the malware protection application. At a minimum, drivers determined to be bad must not be allowed.
Fix
The default behavior is for Early Launch Antimalware - Boot-Start Driver Initialization policy to enforce "Good, unknown and bad but critical" (preventing "bad"). If this needs to be corrected or a more secure setting is desired, configure the policy value for Computer Configuration >> Administrative Templates >> System >> Early Launch Antimalware >> "Boot-Start Driver Initialization Policy" to "Not Configured" or "Enabled" with any option other than "All" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000150: Windows Server 2016 must be configured to audit Account Management - User Account Management failures.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Account Management >> User Account Management - Failure
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. User Account Management records events such as creating, changing, deleting, renaming, disabling, or enabling user accounts. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000476-GPOS-00221
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Account Management >> "Audit User Account Management" with "Failure" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000410: Session security for NTLM SSP-based servers must be configured to require NTLMv2 session security and 128-bit encryption.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\Lsa\MSV1_0\ Value Name: NTLMMinServerSec Value Type: REG_DWORD Value: 0x20080000 (537395200)
Discussion
Microsoft has implemented a variety of security support providers for use with Remote Procedure Call (RPC) sessions. All of the options must be enabled to ensure the maximum security level.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network security: Minimum session security for NTLM SSP based (including secure RPC) servers" to "Require NTLMv2 session security" and "Require 128-bit encryption" (all options selected).
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000090: Active Directory Group Policy objects must have proper access control permissions.
This applies to domain controllers. It is NA for other systems. Review the permissions on Group Policy objects. Open "Group Policy Management" (available from various menus or run "gpmc.msc"). Navigate to "Group Policy Objects" in the domain being reviewed (Forest >> Domains >> Domain). For each Group Policy object: Select the Group Policy object item in the left pane. Select the "Delegation" tab in the right pane. Select the "Advanced" button. Select each Group or user name. View the permissions. If any standard user accounts or groups have "Allow" permissions greater than "Read" and "Apply group policy", this is a finding. Other access permissions that allow the objects to be updated are considered findings unless specifically documented by the ISSO. The default permissions noted below satisfy this requirement. The permissions shown are at the summary level. More detailed permissions can be viewed by selecting the next "Advanced" button, the desired Permission entry, and the "Edit" button. Authenticated Users - Read, Apply group policy, Special permissions The special permissions for Authenticated Users are for Read-type Properties. If detailed permissions include any Create, Delete, Modify, or Write Permissions or Properties, this is a finding. The special permissions for the following default groups are not the focus of this requirement and may include a wide range of permissions and properties. CREATOR OWNER - Special permissions SYSTEM - Read, Write, Create all child objects, Delete all child objects, Special permissions Domain Admins - Read, Write, Create all child objects, Delete all child objects, Special permissions Enterprise Admins - Read, Write, Create all child objects, Delete all child objects, Special permissions ENTERPRISE DOMAIN CONTROLLERS - Read, Special permissions The Domain Admins and Enterprise Admins will not have the "Delete all child objects" permission on the two default Group Policy objects: Default Domain Policy and Default Domain Controllers Policy. They will have this permission on organization created Group Policy objects.
Discussion
When directory service database objects do not have appropriate access control permissions, it may be possible for malicious users to create, read, update, or delete the objects and degrade or destroy the integrity of the data. When the directory service is used for identification, authentication, or authorization functions, a compromise of the database objects could lead to a compromise of all systems relying on the directory service. For Active Directory (AD), the Group Policy objects require special attention. In a distributed administration model (i.e., help desk), Group Policy objects are more likely to have access permissions changed from the secure defaults. If inappropriate access permissions are defined for Group Policy objects, this could allow an intruder to change the security policy applied to all domain client computers (workstations and servers).
Fix
Maintain the permissions on Group Policy objects to not allow greater than "Read" and "Apply group policy" for standard user accounts or groups. The default permissions below meet this requirement. Authenticated Users - Read, Apply group policy, Special permissions The special permissions for Authenticated Users are for Read-type Properties. CREATOR OWNER - Special permissions SYSTEM - Read, Write, Create all child objects, Delete all child objects, Special permissions Domain Admins - Read, Write, Create all child objects, Delete all child objects, Special permissions Enterprise Admins - Read, Write, Create all child objects, Delete all child objects, Special permissions ENTERPRISE DOMAIN CONTROLLERS - Read, Special permissions Document any other access permissions that allow the objects to be updated with the ISSO. The Domain Admins and Enterprise Admins will not have the "Delete all child objects" permission on the two default Group Policy objects: Default Domain Policy and Default Domain Controllers Policy. They will have this permission on created Group Policy objects.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-UR-000010: The Access Credential Manager as a trusted caller user right must not be assigned to any groups or accounts.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups are granted the "Access Credential Manager as a trusted caller" user right, this is a finding. For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs are granted the "SeTrustedCredManAccessPrivilege" user right, this is a finding.
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Access Credential Manager as a trusted caller" user right may be able to retrieve the credentials of other accounts from Credential Manager.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Access Credential Manager as a trusted caller" to be defined but containing no entries (blank).
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-00-000300: The roles and features required by the system must be documented.
Required roles and features will vary based on the function of the individual system. Roles and features specifically required to be disabled per the STIG are identified in separate requirements. If the organization has not documented the roles and features required for the system(s), this is a finding. The PowerShell command "Get-WindowsFeature" will list all roles and features with an "Install State".
Discussion
Unnecessary roles and features increase the attack surface of a system. Limiting roles and features of a system to only those necessary reduces this potential. The standard installation option (previously called Server Core) further reduces this when selected at installation.
Fix
Document the roles and features required for the system to operate. Uninstall any that are not required.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-DC-000180: The Active Directory Domain object must be configured with proper audit settings.
This applies to domain controllers. It is NA for other systems. Review the auditing configuration for the Domain object. Open "Active Directory Users and Computers" (available from various menus or run "dsa.msc"). Ensure "Advanced Features" is selected in the "View" menu. Select the domain being reviewed in the left pane. Right-click the domain name and select "Properties". Select the "Security" tab. Select the "Advanced" button and then the "Auditing" tab. If the audit settings on the Domain object are not at least as inclusive as those below, this is a finding. Type - Fail Principal - Everyone Access - Full Control Inherited from - None Applies to - This object only The success types listed below are defaults. Where Special is listed in the summary screens for Access, detailed Permissions are provided for reference. Various Properties selections may also exist by default. Two instances with the following summary information will be listed. Type - Success Principal - Everyone Access - (blank) Inherited from - None Applies to - Special Type - Success Principal - Domain Users Access - All extended rights Inherited from - None Applies to - This object only Type - Success Principal - Administrators Access - All extended rights Inherited from - None Applies to - This object only Type - Success Principal - Everyone Access - Special Inherited from - None Applies to - This object only (Access - Special = Permissions: Write all properties, Modify permissions, Modify owner)
Discussion
When inappropriate audit settings are configured for directory service database objects, it may be possible for a user or process to update the data without generating any tracking data. The impact of missing audit data is related to the type of object. A failure to capture audit data for objects used by identification, authentication, or authorization functions could degrade or eliminate the ability to track changes to access policy for systems or data. For Active Directory (AD), there are a number of critical object types in the domain naming context of the AD database for which auditing is essential. This includes the Domain object. Because changes to these objects can significantly impact access controls or the availability of systems, the absence of auditing data makes it impossible to identify the source of changes that impact the confidentiality, integrity, and availability of data and systems throughout an AD domain. The lack of proper auditing can result in insufficient forensic evidence needed to investigate an incident and prosecute the intruder. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Open "Active Directory Users and Computers" (available from various menus or run "dsa.msc"). Ensure "Advanced Features" is selected in the "View" menu. Select the domain being reviewed in the left pane. Right-click the domain name and select "Properties". Select the "Security" tab. Select the "Advanced" button and then the "Auditing" tab. Configure the audit settings for Domain object to include the following. Type - Fail Principal - Everyone Access - Full Control Inherited from - None Applies to - This object only The success types listed below are defaults. Where Special is listed in the summary screens for Access, detailed Permissions are provided for reference. Various Properties selections may also exist by default. Two instances with the following summary information will be listed. Type - Success Principal - Everyone Access - (blank) Inherited from - None Applies to - Special Type - Success Principal - Domain Users Access - All extended rights Inherited from - None Applies to - This object only Type - Success Principal - Administrators Access - All extended rights Inherited from - None Applies to - This object only Type - Success Principal - Everyone Access - Special Inherited from - None Applies to - This object only (Access - Special = Permissions: Write all properties, Modify permissions, Modify owner.)
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AC-000060: Windows Server 2016 minimum password age must be configured to at least one day.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Password Policy. If the value for the "Minimum password age" is set to "0" days ("Password can be changed immediately"), this is a finding. For server core installations, run the following command: Secedit /Export /Areas SecurityPolicy /CFG C:\Path\FileName.Txt If "MinimumPasswordAge" equals "0" in the file, this is a finding.
Discussion
Permitting passwords to be changed in immediate succession within the same day allows users to cycle passwords through their history database. This enables users to effectively negate the purpose of mandating periodic password changes.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Password Policy >> "Minimum password age" to at least "1" day.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000360: Windows Server 2016 must be configured to prevent the storage of the LAN Manager hash of passwords.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\Lsa\ Value Name: NoLMHash Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
The LAN Manager hash uses a weak encryption algorithm and there are several tools available that use this hash to retrieve account passwords. This setting controls whether a LAN Manager hash of the password is stored in the SAM the next time the password is changed.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network security: Do not store LAN Manager hash value on next password change" to "Enabled".
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-AU-000286: Windows 2016 must be configured to audit Object Access - Other Object Access Events failures.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the "AuditPol" tool to review the current Audit Policy configuration: Open "PowerShell" or a "Command Prompt" with elevated privileges ("Run as Administrator"). Enter "AuditPol /get /category:*" Compare the "AuditPol" settings with the following: If the system does not audit the following, this is a finding. Object Access >> Other Object Access Events - Failure
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Auditing for other object access records events related to the management of task scheduler jobs and COM+ objects.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Object Access >> "Audit Other Object Access Events" with "Failure" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000270: The Modify firmware environment values user right must only be assigned to the Administrators group.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Modify firmware environment values" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeSystemEnvironmentPrivilege" user right, this is a finding. S-1-5-32-544 (Administrators)
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Modify firmware environment values" user right can change hardware configuration environment variables. This could result in hardware failures or a denial of service.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Modify firmware environment values" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000230: Windows Server 2016 must be configured to audit Logon/Logoff - Account Lockout failures.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*" Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Logon/Logoff >> Account Lockout - Failure
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Account Lockout events can be used to identify potentially malicious logon attempts. Satisfies: SRG-OS-000240-GPOS-00090, SRG-OS-000470-GPOS-00214
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Logon/Logoff >> "Audit Account Lockout" with "Failure" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000220: Users must be prompted to authenticate when the system wakes from sleep (plugged in).
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Power\PowerSettings\0e796bdb-100d-47d6-a2d5-f7d2daa51f51\ Value Name: ACSettingIndex Type: REG_DWORD Value: 0x00000001 (1)
Discussion
A system that does not require authentication when resuming from sleep may provide access to unauthorized users. Authentication must always be required when accessing a system. This setting ensures users are prompted for a password when the system wakes from sleep (plugged in).
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> System >> Power Management >> Sleep Settings >> "Require a password when a computer wakes (plugged in)" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-UR-000310: The Take ownership of files or other objects user right must only be assigned to the Administrators group.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Take ownership of files or other objects" user right, this is a finding. - Administrators For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeTakeOwnershipPrivilege" user right, this is a finding. S-1-5-32-544 (Administrators) If an application requires this user right, this would not be a finding. Vendor documentation must support the requirement for having the user right. The requirement must be documented with the ISSO. The application account must meet requirements for application account passwords, such as length (WN16-00-000060) and required frequency of changes (WN16-00-000070).
Discussion
Inappropriate granting of user rights can provide system, administrative, and other high-level capabilities. Accounts with the "Take ownership of files or other objects" user right can take ownership of objects and make changes.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> "Take ownership of files or other objects" to include only the following accounts or groups: - Administrators
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000100: Command line data must be included in process creation events.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\Audit\ Value Name: ProcessCreationIncludeCmdLine_Enabled Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Enabling "Include command line data for process creation events" will record the command line information with the process creation events in the log. This can provide additional detail when malware has run on a system.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> System >> Audit Process Creation >> "Include command line in process creation events" to "Enabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000460: The Windows Installer Always install with elevated privileges option must be disabled.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\Installer\ Value Name: AlwaysInstallElevated Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Standard user accounts must not be granted elevated privileges. Enabling Windows Installer to elevate privileges when installing applications can allow malicious persons and applications to gain full control of a system.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Windows Installer >> "Always install with elevated privileges" to "Disabled".
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-AC-000020: Windows Server 2016 must have the number of allowed bad logon attempts configured to three or less.
Verify the effective setting in Local Group Policy Editor. Run "gpedit.msc". Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Account Lockout Policy. If the "Account lockout threshold" is "0" or more than "3" attempts, this is a finding. For server core installations, run the following command: Secedit /Export /Areas SecurityPolicy /CFG C:\Path\FileName.Txt If "LockoutBadCount" equals "0" or is greater than "3" in the file, this is a finding.
Discussion
The account lockout feature, when enabled, prevents brute-force password attacks on the system. The higher this value is, the less effective the account lockout feature will be in protecting the local system. The number of bad logon attempts must be reasonably small to minimize the possibility of a successful password attack while allowing for honest errors made during normal user logon.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Account Policies >> Account Lockout Policy >> "Account lockout threshold" to "3" or fewer invalid logon attempts (excluding "0", which is unacceptable).
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000300: Anonymous access to Named Pipes and Shares must be restricted.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\LanManServer\Parameters\ Value Name: RestrictNullSessAccess Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Allowing anonymous access to named pipes or shares provides the potential for unauthorized system access. This setting restricts access to those defined in "Network access: Named Pipes that can be accessed anonymously" and "Network access: Shares that can be accessed anonymously", both of which must be blank under other requirements.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network access: Restrict anonymous access to Named Pipes and Shares" to "Enabled".
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-00-000330: Windows Server 2016 must automatically remove or disable temporary user accounts after 72 hours.
Review temporary user accounts for expiration dates. Determine if temporary user accounts are used and identify any that exist. If none exist, this is NA. Domain Controllers: Open "PowerShell". Enter "Search-ADAccount -AccountExpiring | FT Name, AccountExpirationDate". If "AccountExpirationDate" has not been defined within 72 hours for any temporary user account, this is a finding. Member servers and standalone or nondomain-joined systems: Open "Command Prompt". Run "Net user [username]", where [username] is the name of the temporary user account. If "Account expires" has not been defined within 72 hours for any temporary user account, this is a finding.
Discussion
If temporary user accounts remain active when no longer needed or for an excessive period, these accounts may be used to gain unauthorized access. To mitigate this risk, automated termination of all temporary accounts must be set upon account creation. Temporary accounts are established as part of normal account activation procedures when there is a need for short-term accounts without the demand for immediacy in account activation. If temporary accounts are used, the operating system must be configured to automatically terminate these types of accounts after a DoD-defined time period of 72 hours. To address access requirements, many operating systems may be integrated with enterprise-level authentication/access mechanisms that meet or exceed access control policy requirements.
Fix
Configure temporary user accounts to automatically expire within 72 hours. Domain accounts can be configured with an account expiration date under "Account" properties. Local accounts can be configured to expire with the command "Net user [username] /expires:[mm/dd/yyyy]", where username is the name of the temporary user account. Delete any temporary user accounts that are no longer necessary.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000420: Windows Server 2016 must be configured to audit System - Security System Extension successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. System >> Security System Extension - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Security System Extension records events related to extension code being loaded by the security subsystem. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000458-GPOS-00203, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> System >> "Audit Security System Extension" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000260: The default AutoRun behavior must be configured to prevent AutoRun commands.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\ Value Name: NoAutorun Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Allowing AutoRun commands to execute may introduce malicious code to a system. Configuring this setting prevents AutoRun commands from executing.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> AutoPlay Policies >> "Set the default behavior for AutoRun" to "Enabled" with "Do not execute any autorun commands" selected.
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-DC-000140: Separate, NSA-approved (Type 1) cryptography must be used to protect the directory data in transit for directory service implementations at a classified confidentiality level when replication data traverses a network cleared to a lower level than the data.
This applies to domain controllers. It is NA for other systems. Review the organization network diagram(s) or documentation to determine the level of classification for the network(s) over which replication data is transmitted. Determine the classification level of the Windows domain controller. If the classification level of the Windows domain controller is higher than the level of the networks, review the organization network diagram(s) and directory implementation documentation to determine if NSA-approved encryption is used to protect the replication network traffic. If the classification level of the Windows domain controller is higher than the level of the network traversed and NSA-approved encryption is not used, this is a finding.
Discussion
Directory data that is not appropriately encrypted is subject to compromise. Commercial-grade encryption does not provide adequate protection when the classification level of directory data in transit is higher than the level of the network.
Fix
Configure NSA-approved (Type 1) cryptography to protect the directory data in transit for directory service implementations at a classified confidentiality level that transfer replication data through a network cleared to a lower level than the data.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-SO-000260: Anonymous enumeration of Security Account Manager (SAM) accounts must not be allowed.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\Lsa\ Value Name: RestrictAnonymousSAM Value Type: REG_DWORD Value: 0x00000001 (1)
Discussion
Anonymous enumeration of SAM accounts allows anonymous logon users (null session connections) to list all accounts names, thus providing a list of potential points to attack the system.
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network access: Do not allow anonymous enumeration of SAM accounts" to "Enabled".
Rating Info
DISA Cat I. NIST impact 4.
Expert Comment
None
WN16-00-000200: Non-administrative accounts or groups must only have print permissions on printer shares.
Open "Devices and Printers". If there are no printers configured, this is NA. (Exclude Microsoft Print to PDF and Microsoft XPS Document Writer, which do not support sharing.) For each printer: Right-click on the printer. Select "Printer Properties". Select the "Sharing" tab. If "Share this printer" is checked, select the "Security" tab. If any standard user accounts or groups have permissions other than "Print", this is a finding. The default is for the "Everyone" group to be given "Print" permission. "All APPLICATION PACKAGES" and "CREATOR OWNER" are not standard user accounts.
Discussion
Windows shares are a means by which files, folders, printers, and other resources can be published for network users to access. Improper configuration can permit access to devices and data beyond a user's need.
Fix
Configure the permissions on shared printers to restrict standard users to only have Print permissions.
Rating Info
DISA Cat III. NIST impact 2.
Expert Comment
None
WN16-00-000390: The Telnet Client must not be installed.
Open "PowerShell". Enter "Get-WindowsFeature | Where Name -eq Telnet-Client". If "Installed State" is "Installed", this is a finding. An Installed State of "Available" or "Removed" is not a finding.
Discussion
Unnecessary services increase the attack surface of a system. Some of these services may not support required levels of authentication or encryption or may provide unauthorized access to the system.
Fix
Uninstall the "Telnet Client" feature. Start "Server Manager". Select the server with the feature. Scroll down to "ROLES AND FEATURES" in the right pane. Select "Remove Roles and Features" from the drop-down "TASKS" list. Select the appropriate server on the "Server Selection" page and click "Next". Deselect "Telnet Client" on the "Features" page. Click "Next" and "Remove" as prompted.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-AU-000330: Windows Server 2016 must be configured to audit Policy Change - Authentication Policy Change successes.
Security Option "Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings" must be set to "Enabled" (WN16-SO-000050) for the detailed auditing subcategories to be effective. Use the AuditPol tool to review the current Audit Policy configuration: Open an elevated "Command Prompt" (run as administrator). Enter "AuditPol /get /category:*". Compare the AuditPol settings with the following. If the system does not audit the following, this is a finding. Policy Change >> Authentication Policy Change - Success
Discussion
Maintaining an audit trail of system activity logs can help identify configuration errors, troubleshoot service disruptions, and analyze compromises that have occurred, as well as detect attacks. Audit logs are necessary to provide a trail of evidence in case the system or network is compromised. Collecting this data is essential for analyzing the security of information assets and detecting signs of suspicious and unexpected behavior. Authentication Policy Change records events related to changes in authentication policy, including Kerberos policy and Trust changes. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000064-GPOS-00033, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210
Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Advanced Audit Policy Configuration >> System Audit Policies >> Policy Change >> "Audit Authentication Policy Change" with "Success" selected.
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000290: Windows Telemetry must be configured to Security or Basic.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\DataCollection\ Value Name: AllowTelemetry Type: REG_DWORD Value: 0x00000000 (0) (Security), 0x00000001 (1) (Basic)
Discussion
Some features may communicate with the vendor, sending system information or downloading data or components for the feature. Limiting this capability will prevent potentially sensitive information from being sent outside the enterprise. The "Security" option for Telemetry configures the lowest amount of data, effectively none outside of the Malicious Software Removal Tool (MSRT), Defender, and telemetry client settings. "Basic" sends basic diagnostic and usage data and may be required to support some Microsoft services.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Data Collection and Preview Builds>> "Allow Telemetry" to "Enabled" with "0 - Security [Enterprise Only]" or "1 - Basic" selected in "Options".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
None
WN16-CC-000080: Insecure logons to an SMB server must be disabled.
If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\LanmanWorkstation\ Value Name: AllowInsecureGuestAuth Type: REG_DWORD Value: 0x00000000 (0)
Discussion
Insecure guest logons allow unauthenticated access to shared folders. Shared resources on a system must require authentication to establish proper access.
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Network >> Lanman Workstation >> "Enable insecure guest logons" to "Disabled".
Rating Info
DISA Cat II. NIST impact 3.
Expert Comment
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