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.