7.1.6 Ensure permissions on /etc/shadow- are configured

Information

The /etc/shadow- file is used to store backup information about user accounts that is critical to the security of those accounts, such as the hashed password and other security information.

It is critical to ensure that the /etc/shadow- 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 one of the following commands to set ownership of /etc/shadow- to root and group to either root or shadow :

# chown root:shadow /etc/shadow-
-OR-
# chown root:root /etc/shadow-

Run the following command to remove excess permissions form /etc/shadow- :

# chmod u-x,g-wx,o-rwx /etc/shadow-

See Also

https://workbench.cisecurity.org/benchmarks/18959