Vulnerability Discussion

If a user is assigned the GID of a group not existing on the system, and a group with the GID is subsequently created, the user may have unintended rights to any files associated with the group.

Check

Verify all GIDs referenced in the "/etc/passwd" file are defined in the "/etc/group" file.

Check that all referenced GIDs exist with the following command:

# pwck -r

If GIDs referenced in then "/etc/passwd" file are returned as not defined in the "/etc/group" file, this is a finding.

Fix

Configure the system to define all GIDs found in the "/etc/passwd" file by modifying the "/etc/group" file to add any non-existent group referenced in the "/etc/passwd" file, or change the GIDs referenced in the "/etc/passwd" file to a group that exists in "/etc/group".