AC-19(4)_restrictions-for-classified-information

AC-19(4) Restrictions for Classified Information

Enhancement of: AC-19

High-Level Description

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

None.

What to Check

• Verify AC-19(4) Restrictions for Classified Information is documented in SSP
• Validate all 5 control requirements are implemented
• Confirm control is operating effectively
• Review evidence of continuous monitoring for AC-19(4)
• Verify enhancement builds upon base control AC-19

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for AC-19(4) 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

Prohibit the use of unclassified mobile devices in facilities containing systems processing, storing, or transmitting classified information unless specifically permitted by the authorizing official; and Enforce the following restrictions on individuals permitted by the authorizing official to use unclassified mobile devices in facilities containing systems processing, storing, or transmitting classified information: Connection of unclassified mobile devices to classified systems is prohibited; Connection of unclassified mobile devices to unclassified systems requires approval from the authorizing official; Use of internal or external modems or wireless interfaces within the unclassified mobile devices is prohibited; and Unclassified mobile devices and the information stored on those devices are subject to random reviews and inspections by [organization-defined] , and if classified information is found, the incident handling policy is followed. Restrict the connection of classified mobile devices to classified systems in accordance with [organization-defined].

Implementation Guidance

None.

Risk Assessment

CWE Categories

References

• NIST SP 800-53 Rev 5 - AC-19(4)
• 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 (CM-8, IR-4) reviewed