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. "pwquality" enforces complex password construction configuration and has the ability to limit brute-force attacks on the system.

RHEL 8 utilizes "pwquality" as a mechanism to enforce password complexity. This is set in both:
/etc/pam.d/password-auth
/etc/pam.d/system-auth

Note the value of "retry" set in these configuration files should be between "1" and "3". Manual changes to the listed files may be overwritten by the "authselect" program.

Check

Verify the operating system uses "pwquality" to enforce the password complexity rules.

Check for the use of "pwquality" with the following commands:

$ sudo cat /etc/pam.d/password-auth | grep pam_pwquality

password required pam_pwquality.so retry=3

$ sudo cat /etc/pam.d/system-auth | grep pam_pwquality

password required pam_pwquality.so retry=3

If both commands do not return a line containing the value "pam_pwquality.so", or the line is commented out, this is a finding.

If the value of "retry" is set to "0" or greater than "3", this is a finding.

Fix

Configure the operating system to use "pwquality" to enforce password complexity rules.

Add the following line to both "/etc/pam.d/password-auth" and "/etc/pam.d/system-auth" (or modify the line to have the required value):

password required pam_pwquality.so retry=3