Vulnerability Discussion

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.

Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.

OL 8 uses "pwquality" as a mechanism to enforce password complexity. The "difok" option sets the number of characters in a password that must not be present in the old password.

Check

Verify the value of the "difok" option in "/etc/security/pwquality.conf" or "/etc/security/pwquality.conf.d/*.conf" files with the following command:

$ sudo grep -r difok /etc/security/pwquality.conf*

/etc/security/pwquality.conf:difok = 8

If the value of "difok" is set to less than "8" or is commented out, this is a finding.
If conflicting results are returned, this is a finding.

Fix

Configure OL 8 to require the change of at least eight of the total number of characters when passwords are changed by setting the "difok" option.

Add or update the following line in the "/etc/security/pwquality.conf" file or a configuration file in the "/etc/security/pwquality.conf.d/" directory:

difok = 8

Remove any configurations that conflict with the above value.