au-9-1-hardware-write-once-media

name	AU-9(1)_hardware-write-once-media
description	Write audit trails to hardware-enforced, write-once media.
category	information-gathering
version	5.2.0
author	cyberstrike-official
tags	["nist","sp800-53","rev5","au-9-1","au","enhancement"]
tech_stack	["aws","azure","gcp","linux","windows"]
cwe_ids	["CWE-778"]
chains_with	["AU-4","AU-5"]
prerequisites	["AU-9"]
severity_boost	{"AU-4":"Chain with AU-4 for comprehensive security coverage","AU-5":"Chain with AU-5 for comprehensive security coverage"}

AU-9(1) Hardware Write-once Media

Enhancement of: AU-9

High-Level Description

Family: Audit and Accountability (AU) Framework: NIST SP 800-53 Rev 5

Writing audit trails to hardware-enforced, write-once media applies to the initial generation of audit trails (i.e., the collection of audit records that represents the information to be used for detection, analysis, and reporting purposes) and to the backup of those audit trails. Writing audit trails to hardware-enforced, write-once media does not apply to the initial generation of audit records prior to being written to an audit trail. Write-once, read-many (WORM) media includes Compact Disc-Recordable (CD-R), Blu-Ray Disc Recordable (BD-R), and Digital Versatile Disc-Recordable (DVD-R). In contrast, the use of switchable write-protection media, such as tape cartridges, Universal Serial Bus (USB) drives, Compact Disc Re-Writeable (CD-RW), and Digital Versatile Disc-Read Write (DVD-RW) results in write-protected but not write-once media.

What to Check

• Verify AU-9(1) Hardware Write-once Media is documented in SSP
• Confirm control is operating effectively
• Review evidence of continuous monitoring for AU-9(1)
• Verify enhancement builds upon base control AU-9

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for AU-9(1) implementation details. Verify the organization has documented how this control is satisfied.

Step 2: Validate Implementation

# For cloud environments, use cloud-audit-mcp tools
# For on-premises, review system configurations directly

# Example: Check if account management policies exist
grep -r "account.management\|access.control" /etc/security/ 2>/dev/null

Step 3: Test Operating Effectiveness

Verify the control is actively functioning, not just documented. Check logs, configurations, and operational evidence.

Tools

Tool	Purpose	Usage
cloud-audit-mcp	Check logging configuration	cloud_audit_logging
AWS CLI	Review CloudTrail/CloudWatch	aws cloudtrail describe-trails