The operating system must store only encrypted representations of passwords.

Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised.

At the command line, run the following command to verify passwords are stored with only encrypted representations:

# grep ^ENCRYPT_METHOD /etc/login.defs

Example result:

ENCRYPT_METHOD SHA512

If the "ENCRYPT_METHOD" option is not set to "SHA512", is missing or commented out, this is a finding.

Navigate to and open:

/etc/login.defs

Add or update the following line:

ENCRYPT_METHOD SHA512