Information
The /etc/passwd.old file contains backup user account information.
Rationale:
It is critical to ensure that the /etc/passwd.old file is protected from unauthorized access. Although it is protected by default, the file permissions could be changed either inadvertently or through malicious actions.
Solution
Run the following command to set permissions on /etc/passwd.old:
# chown root:root /etc/passwd.old
# chmod u-x,go-wx /etc/passwd.old