Title

Permissions for system files and directories must conform to minimum requirements. (Cat II impact)

Discussion

Changing the system's file and directory permissions allows the possibility of unauthorized and anonymous modification to the operating system and installed applications.

Check Content

The default ACL settings are adequate when the Security Option "Network access: Let Everyone permissions apply to anonymous users" is set to "Disabled" (V-3377). If the default ACLs are maintained and the referenced option is set to "Disabled", this is not a finding. Verify the default permissions for the sample directories below. 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.) Viewing in File Explorer: Select the "Security" tab, and the "Advanced" button. C:\ Type - "Allow" for all Inherited from - "None" for all Principal - Access - Applies to Administrators - Full control - This folder, subfolders and files SYSTEM - Full control - This folder, subfolders and files Users - Read & execute - This folder, subfolders and files Authenticated Users - Modify - Subfolders and files only Authenticated Users - Create folders / append data - This folder only \Program Files 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 \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 Alternately use Icacls. In a Command prompt (admin) Enter icacls followed by the directory. icacls c:\ icacls "c:\program files" icacls c:\windows The following results will be displayed as each is entered: c:\ BUILTIN\Administrators:(OI)(CI)(F) NT AUTHORITY\SYSTEM:(OI)(CI)(F) BUILTIN\Users:(OI)(CI)(RX) NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(M) NT AUTHORITY\Authenticated Users:(AD) Mandatory Label\High Mandatory Level:(OI)(NP)(IO)(NW) Successfully processed 1 files; Failed processing 0 files c:\program files 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) Successfully processed 1 files; Failed processing 0 files 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) Successfully processed 1 files; Failed processing 0 files If an ACL setting prevents a site's applications from performing properly, settings must only be changed to the minimum necessary for the application to function. Each exception must be documented with the ISSO.

Fix Text

Maintain the default file ACLs and configure the Security Option: "Network access: Let everyone permissions apply to anonymous users" to "Disabled" (V-3377).

Additional Identifiers

Rule ID: SV-48040r2_rule

Vulnerability ID: V-1130

Group Title: System File ACLs

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.