Vulnerability Discussion
If the "/etc/passwd" file is writable by a group-owner or the world the risk of its compromise is increased. The file contains the list of accounts on the system and associated information, and protection of this file is critical for system security.
Check
Verify that the "/etc/passwd" file has mode "0644" or less permissive with the following command:
$ sudo stat -c "%a %n" /etc/passwd
644 /etc/passwd
If a value of "0644" or less permissive is not returned, this is a finding.
Fix
Change the mode of the file "/etc/passwd" to "0644" by running the following command:
$ sudo chmod 0644 /etc/passwd