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.

Satisfies: SRG-OS-000078-GPOS-00046, SRG-OS-000725-GPOS-00180

Check

Verify Amazon Linux 2023 enforces a minimum 15-character password length with the following command:

$ sudo grep -rs 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 the line is commented out, this is a finding.

If conflicting results are returned, this is a finding.

Fix

Configure Amazon Linux 2023 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 to contain the "minlen" parameter:

minlen = 15

Remove any configurations that conflict with the above value.