Title

Windows Server 2019 must have orphaned security identifiers (SIDs) removed from user rights. (Cat II impact)

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.

Check Content

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 that begins with "*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

Fix Text

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.

Additional Identifiers

Rule ID: SV-205855r991589_rule

Vulnerability ID: V-205855

Group Title: SRG-OS-000480-GPOS-00227

Expert Comments

CCIs tied to check.

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