RHEL 9 groups must have unique Group ID (GID).

STIG ID: RHEL-09-411110  |  SRG: SRG-OS-000104-GPOS-00051 |  Severity: medium |  CCI: CCI-000764 |  Vulnerability Id: V-258061 | 

Vulnerability Discussion

To ensure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system.

Check

Verify that RHEL 9 contains no duplicate GIDs for interactive users with the following command:

$ cut -d : -f 3 /etc/group | uniq -d

If the system has duplicate GIDs, this is a finding.

Fix

Edit the file "/etc/group" and provide each group that has a duplicate GID with a unique GID.