cis-ubuntu2004-v300-5-3-3-3-2

DevOps & Security

Ensure password history is enforced for the root user

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5.3.3.3.2 Ensure password history is enforced for the root user (Automated)

Profile Applicability

Level 1 - Server
Level 1 - Workstation

Description

If the pwhistory enforce_for_root option is enabled, the module will enforce password history for the root user as well.

Rationale

Requiring users not to reuse their passwords make it less likely that an attacker will be able to guess the password or use a compromised password.

Note: These change only apply to accounts configured on the local system.

Audit Procedure

Command Line

Run the following command to verify that the enforce_for_root argument is exists on the pwhistory line in /etc/pam.d/common-password:

# grep -Psi -- '^\h*password\h+[^#\n\r]+\h+pam_pwhistory\.so\h+([^#\n\r]+\h+)?enforce_for_root\b' /etc/pam.d/common-password

Expected Result

Output should be similar to:

password   requisite   pam_pwhistory.so remember=24 enforce_for_root use_authtok

Remediation

Command Line

Run the following command:

# awk '/Password-Type:/{ f = 1;next } /-Type:/{ f = 0 } f {if (/pam_pwhistory\.so/) print FILENAME}' /usr/share/pam-configs/*

Edit any returned files and add the enforce_for_root argument to the pam_pwhistory line in the Password section:

Example File:

Name: pwhistory password history checking
Default: yes
Priority: 1024
Password-Type: Primary
Password:
   requisite   pam_pwhistory.so remember=24 enforce_for_root use_authtok # <- **ensure line includes enforce_for_root**

Run the following command to update the files in the /etc/pam.d/ directory:

# pam-auth-update --enable <MODIFIED_PROFILE_NAME>

Example:

# pam-auth-update --enable pwhistory

Default Value

disabled

References

NIST SP 800-53 Rev. 5: IA-5

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	5.2 Use Unique Passwords	*	*	*
v7	4.4 Use Unique Passwords		*	*

MITRE ATT&CK Mappings

Techniques / Sub-techniques	Tactics	Mitigations
T1110, T1110.001, T1110.002, T1110.003, T1178.001, T1178.002, T1178.003, T1178.004	TA0006	M1027