Vulnerability Discussion
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 exponentially increase the time and/or resources required to compromise the password.
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" with the following command:
# grep minlen /etc/security/pwquality.conf
minlen = 15
If the command does not return a "minlen" value of 15 or greater, this is a finding.
Fix
Configure operating system to enforce a minimum 15-character password length.
Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value):
minlen = 15