AC-4(22)_access-only

AC-4(22) Access Only

Enhancement of: AC-4

High-Level Description

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

The system provides a capability for users to access each connected security domain without providing any mechanisms to allow users to transfer data or information between the different security domains. An example of an access-only solution is a terminal that provides a user access to information with different security classifications while assuredly keeping the information separate.

What to Check

• Verify AC-4(22) Access Only is documented in SSP
• Confirm control is operating effectively
• Review evidence of continuous monitoring for AC-4(22)
• 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(22) 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

Remediation Guide

Control Statement

Provide access from a single device to computing platforms, applications, or data residing in multiple different security domains, while preventing information flow between the different security domains.

Implementation Guidance

The system provides a capability for users to access each connected security domain without providing any mechanisms to allow users to transfer data or information between the different security domains. An example of an access-only solution is a terminal that provides a user access to information with different security classifications while assuredly keeping the information separate.

Risk Assessment

CWE Categories

References

• NIST SP 800-53 Rev 5 - AC-4(22)
• NIST SP 800-53A Rev 5 (Assessment Procedures)
• NIST SP 800-53 Rev 5 Full Catalog

Checklist

• Control documented in SSP
• Implementation evidence collected
• Operating effectiveness validated
• Continuous monitoring in place
• Related controls (none) reviewed