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.

Using more hashing rounds makes password cracking attacks more difficult.

Satisfies: SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061

Check

Verify the number of rounds for the password hashing algorithm is configured with the following command:

$ sudo grep rounds /etc/pam.d/system-auth

password sufficient pam_unix.so sha512 rounds=100000

If a matching line is not returned or "rounds" is less than 100000, this a finding.

Fix

Configure RHEL 9 to use 100000 hashing rounds for hashing passwords.

Add or modify the following line in "/etc/pam.d/system-auth" and set "rounds" to 100000.

password sufficient pam_unix.so sha512 rounds=100000

Note: Running authselect will overwrite this value unless a custom authselect policy is created.