# Ensure Password History Is Enforced for the Root User

- Source: https://support.icompaas.com/support/solutions/articles/62000235461-ensure-password-history-is-enforced-for-the-root-user
- Section: [Solutions](https://support.icompaas.com/support/solutions) › [CIS Amazon Linux 2 Benchmark v3.0.0](https://support.icompaas.com/support/solutions/62000112696) › [CIS Amazon Linux 2 Benchmarks](https://support.icompaas.com/support/solutions/folders/62000169265)
- Last updated: 2026-05-29
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

**Profile Applicability:** • Level 1

**Description:** Enforcing password history for the root user prevents reuse of recently used passwords, enhancing the security of the most privileged account by ensuring password changes involve new and unique values.

**Rationale:** Applying password history enforcement to the root account reduces the risk of password reuse attacks and strengthens overall system security by protecting the highest privilege level.

**Impact:** Pros:

-   Enhances protection of the root account.  
    
-   Supports compliance with strict security policies.  
    

Cons:

-   May increase administrative overhead for root password management.  
    

**Default Value:** Password history enforcement may not be enabled for the root user by default.

**Pre-requisites:**

-   Root or sudo privileges to modify PAM configuration.  
    

**Remediation:**

### **Test Plan:**

**Using Linux command line:**

1.  Check PAM configuration files for enforcement on root user:  
    
2.  grep pam\_pwhistory /etc/pam.d/system-auth  
    grep pam\_pwhistory /etc/pam.d/common-password
    
3.  Verify the presence of enforce\_for\_root option in the pam\_pwhistory module configuration.
    

### **Implementation Plan:**

**Using Linux command line:**

1\. Edit PAM password configuration file:  

vi /etc/pam.d/system-auth

2\. Ensure the line enabling pam\_pwhistory includes enforce\_for\_root:  

password required pam\_pwhistory.so use\_authok remember=5 enforce\_for\_root

3\. Save the file.  

### **Backout Plan:**

**Using Linux command line:**

1.  Remove the enforce\_for\_root option if necessary.
    
2.  Test password changes to confirm behavior.  
    

**References:**

-   CIS Amazon Linux 2 Benchmark v3.0.0  
    
-   pam\_pwhistory Documentation  
    
-   [NIST SP 800-63B - Digital Identity Guidelines  
    ](https://pages.nist.gov/800-63-3/sp800-63b.html)

## Related compliance guidance

- [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Configuration checks like this one are the technical half of a SOC 2 / ISO 27001 programme — the guide shows where they fit, what else an auditor expects, and how to evidence them.
- [ISO/IEC 27001:2022 compliance: a practical implementation guide](https://support.icompaas.com/compliance/iso-27001-2022): ISO 27001 Annex A.8 (technological controls) is where cloud hardening evidence lands; the guide shows how to run the ISMS around it.