Vulnerability Discussion

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. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text.

This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the "crypt_style" configuration option ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult.

Check

Verify the system's shadow file is configured to store only encrypted representations of passwords with a hash value of SHA512 with the following command:

# grep -i encrypt_method /etc/login.defs

ENCRYPT_METHOD SHA512

If "ENCRYPT_METHOD" does not have a value of "SHA512", or the line is commented out, this is a finding.

Fix

Configure RHEL 9 to store only SHA512 encrypted representations of passwords.

Add or update the following line in the "/etc/login.defs" file:

ENCRYPT_METHOD SHA512