Vulnerability Discussion
The "/etc/passwd-" file is a backup file of "/etc/passwd", and as such, contains information about the users that are configured on the system. Protection of this file is critical for system security.
Check
Verify the group ownership of the "/etc/passwd-" file with the following command:
$ sudo stat -c "%G %n" /etc/passwd-
root /etc/passwd-
If "/etc/passwd-" file does not have a group owner of "root", this is a finding.
Fix
Change the group of the file /etc/passwd- to root by running the following command:
$ sudo chgrp root /etc/passwd-