RHEL 8 passwords for new users must have a minimum of 15 characters.

The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised.

Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to increase exponentially the time and/or resources required to compromise the password.

The DoD minimum password requirement is 15 characters.

Verify that RHEL 8 enforces a minimum 15-character password length for new user accounts by running the following command:

$ sudo grep -i  pass_min_len /etc/login.defs

PASS_MIN_LEN 15

If the "PASS_MIN_LEN" parameter value is less than "15", or commented out, this is a finding.

Configure operating system to enforce a minimum 15-character password length for new user accounts.

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

PASS_MIN_LEN 15