ac-4-19-validation-of-metadata

name	AC-4(19)_validation-of-metadata
description	When transferring information between different security domains, implement [organization-defined] on metadata.
category	authorization
version	5.2.0
author	cyberstrike-official
tags	["nist","sp800-53","rev5","ac-4-19","ac","enhancement"]
tech_stack	["aws","azure","gcp","linux","windows"]
cwe_ids	["CWE-284"]
chains_with	[]
prerequisites	["AC-4"]
severity_boost	{}

AC-4(19) Validation of Metadata

Enhancement of: AC-4

High-Level Description

Family: Access Control (AC) Framework: NIST SP 800-53 Rev 5

All information (including metadata and the data to which the metadata applies) is subject to filtering and inspection. Some organizations distinguish between metadata and data payloads (i.e., only the data to which the metadata is bound). Other organizations do not make such distinctions and consider metadata and the data to which the metadata applies to be part of the payload.

What to Check

• Verify AC-4(19) Validation of Metadata is documented in SSP
• Confirm control is operating effectively
• Review evidence of continuous monitoring for AC-4(19)
• Verify enhancement builds upon base control AC-4

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for AC-4(19) 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 IAM policies and access controls	cloud_audit_iam_policies
hackbrowser-mcp	Test web application access controls	browser_auth_test

Remediation Guide

Control Statement

When transferring information between different security domains, implement [organization-defined] on metadata.

Implementation Guidance

All information (including metadata and the data to which the metadata applies) is subject to filtering and inspection. Some organizations distinguish between metadata and data payloads (i.e., only the data to which the metadata is bound). Other organizations do not make such distinctions and consider metadata and the data to which the metadata applies to be part of the payload.