Vulnerability Discussion
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.
OL 8 uses "pwquality" as a mechanism to enforce password complexity. Configurations are set in the "etc/security/pwquality.conf" file.
The "minlen", sometimes noted as minimum length, acts as a "score" of complexity based on the credit components of the "pwquality" module. By setting the credit components to a negative value, not only will those components be required, but they will not count toward the total "score" of "minlen". This will enable "minlen" to require a 15-character minimum.
Check
Verify the operating system enforces a minimum 15-character password length. The "minlen" option sets the minimum number of characters in a new password.
Check for the value of the "minlen" option in "/etc/security/pwquality.conf" or "/etc/security/pwquality.conf.d/*.conf" files with the following command:
$ sudo grep minlen /etc/security/pwquality.conf /etc/security/pwquality.conf.d/*.conf
/etc/security/pwquality.conf:minlen = 15
If the command does not return a "minlen" value of 15 or greater or is commented out, this is a finding.
Fix
Configure OL 8 to enforce a minimum 15-character password length.
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:
minlen = 15