The Ubuntu operating system must prohibit password reuse for a minimum of five generations.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-238234	UBTU-20-010070	SV-238234r832945_rule		Low

Description
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. If the information system or application allows the user to consecutively reuse their password when that password has exceeded its defined lifetime, the end result is a password that is not changed as per policy requirements. Satisfies: SRG-OS-000077-GPOS-00045, SRG-OS-000073-GPOS-00041

Description

Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. If the information system or application allows the user to consecutively reuse their password when that password has exceeded its defined lifetime, the end result is a password that is not changed as per policy requirements. Satisfies: SRG-OS-000077-GPOS-00045, SRG-OS-000073-GPOS-00041

STIG	Date
Canonical Ubuntu 20.04 LTS Security Technical Implementation Guide	2023-06-02

Details

Check Text ( C-41444r832943_chk )
Verify the Ubuntu operating system prevents passwords from being reused for a minimum of five generations by running the following command: $ grep -i remember /etc/pam.d/common-password password [success=1 default=ignore] pam_unix.so obscure sha512 shadow remember=5 rounds=5000 If the "remember" parameter value is not greater than or equal to "5", is commented out, or is not set at all, this is a finding.

Check Text ( C-41444r832943_chk )

Verify the Ubuntu operating system prevents passwords from being reused for a minimum of five generations by running the following command:

$ grep -i remember /etc/pam.d/common-password

password [success=1 default=ignore] pam_unix.so obscure sha512 shadow remember=5 rounds=5000

If the "remember" parameter value is not greater than or equal to "5", is commented out, or is not set at all, this is a finding.

Fix Text (F-41403r832944_fix)
Configure the Ubuntu operating system to prevent passwords from being reused for a minimum of five generations. Add or modify the "remember" parameter value to the following line in "/etc/pam.d/common-password" file: password [success=1 default=ignore] pam_unix.so obscure sha512 shadow remember=5 rounds=5000