The Ubuntu operating system must be configured so that when passwords are changed or new passwords are established, pwquality must be used.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-238228	SRG-OS-000480-GPOS-00225	UBTU-20-010057	SV-238228r991587_rule	2025-03-03	2

Description
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. "pwquality" enforces complex password construction configuration and has the ability to limit brute-force attacks on the system.

ℹ️ Check
Verify the Ubuntu operating system has the "libpam-pwquality" package installed by running the following command: $ dpkg -l libpam-pwquality ii libpam-pwquality:amd64 1.4.0-2 amd64 PAM module to check password strength If "libpam-pwquality" is not installed, this is a finding. Verify that the operating system uses "pwquality" to enforce the password complexity rules. Verify the pwquality module is being enforced by the Ubuntu operating system by running the following command: $ grep -i enforcing /etc/security/pwquality.conf enforcing = 1 If the value of "enforcing" is not "1" or the line is commented out, this is a finding. Check for the use of "pwquality" with the following command: $ cat /etc/pam.d/common-password \| grep requisite \| grep pam_pwquality password requisite pam_pwquality.so retry=3 If no output is returned or the line is commented out, this is a finding. If the value of "retry" is set to "0" or greater than "3", this is a finding.

ℹ️ Check

Verify the Ubuntu operating system has the "libpam-pwquality" package installed by running the following command: $ dpkg -l libpam-pwquality ii libpam-pwquality:amd64 1.4.0-2 amd64 PAM module to check password strength If "libpam-pwquality" is not installed, this is a finding. Verify that the operating system uses "pwquality" to enforce the password complexity rules. Verify the pwquality module is being enforced by the Ubuntu operating system by running the following command: $ grep -i enforcing /etc/security/pwquality.conf enforcing = 1 If the value of "enforcing" is not "1" or the line is commented out, this is a finding. Check for the use of "pwquality" with the following command: $ cat /etc/pam.d/common-password | grep requisite | grep pam_pwquality password requisite pam_pwquality.so retry=3 If no output is returned or the line is commented out, this is a finding. If the value of "retry" is set to "0" or greater than "3", this is a finding.

✔️ Fix
Configure the operating system to use "pwquality" to enforce password complexity rules. Install the "pam_pwquality" package by using the following command: $ sudo apt-get install libpam-pwquality -y Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): enforcing = 1 Add the following line to "/etc/pam.d/common-password" (or modify the line to have the required value): password requisite pam_pwquality.so retry=3 Note: The value of "retry" should be between "1" and "3".

✔️ Fix

Configure the operating system to use "pwquality" to enforce password complexity rules. Install the "pam_pwquality" package by using the following command: $ sudo apt-get install libpam-pwquality -y Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): enforcing = 1 Add the following line to "/etc/pam.d/common-password" (or modify the line to have the required value): password requisite pam_pwquality.so retry=3 Note: The value of "retry" should be between "1" and "3".