Title

Permissions for Windows installation directory 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. The default permissions are adequate when the Security Option "Network access: Let everyone permissions apply to anonymous users" is set to "Disabled" (V-3377).

Check Content

The default permissions 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 Windows installation directory (usually C:\Windows). Nonprivileged 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: View the Properties of the folder. 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 Alternately, use Icacls: Open a Command prompt (admin). Enter icacls followed by the directory: icacls c:\windows The following results should be displayed: 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

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). 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

Additional Identifiers

Rule ID: SV-225422r852236_rule

Vulnerability ID: V-225422

Group Title: SRG-OS-000259-GPOS-00100

Expert Comments

CCIs tied to check.

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