Information
The /etc/passwd file contains user account information that is used by many system utilities and therefore must be readable for these utilities to operate.
It is critical to ensure that the /etc/passwd file is protected from unauthorized write access. Although it is protected by default, the file permissions could be changed either inadvertently or through malicious actions.
Solution
Run the following commands to remove excess permissions, set owner, and set group on /etc/passwd :
# chmod u-x,go-wx /etc/passwd
# chown root:root /etc/passwd