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.

Satisfies: SRG-OS-000070-GPOS-00038, SRG-OS-000730-GPOS-00190

Check

Verify Ubuntu 24.04 LTS enforces password complexity by requiring that at least one lowercase character be used with the following command:

$ grep -i "lcredit" /etc/security/pwquality.conf
lcredit=-1

If the "lcredit" parameter is greater than "-1", is commented out, or is missing, this is a finding.

Fix

Configure Ubuntu 24.04 LTS to enforce password complexity by requiring that at least one lowercase character be used.

Add or update the "/etc/security/pwquality.conf" file to contain the "lcredit" parameter:

lcredit=-1