AC-18(5)_antennas-and-transmission-power-levels

AC-18(5) Antennas and Transmission Power Levels

Enhancement of: AC-18

High-Level Description

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

Actions that may be taken to limit unauthorized use of wireless communications outside of organization-controlled boundaries include reducing the power of wireless transmissions so that the transmissions are less likely to emit a signal that can be captured outside of the physical perimeters of the organization, employing measures such as emissions security to control wireless emanations, and using directional or beamforming antennas that reduce the likelihood that unintended receivers will be able to intercept signals. Prior to taking such mitigating actions, organizations can conduct periodic wireless surveys to understand the radio frequency profile of organizational systems as well as other systems that may be operating in the area.

What to Check

• Verify AC-18(5) Antennas and Transmission Power Levels is documented in SSP
• Confirm control is operating effectively
• Review evidence of continuous monitoring for AC-18(5)
• Verify enhancement builds upon base control AC-18

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for AC-18(5) 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

Select radio antennas and calibrate transmission power levels to reduce the probability that signals from wireless access points can be received outside of organization-controlled boundaries.

Implementation Guidance

Actions that may be taken to limit unauthorized use of wireless communications outside of organization-controlled boundaries include reducing the power of wireless transmissions so that the transmissions are less likely to emit a signal that can be captured outside of the physical perimeters of the organization, employing measures such as emissions security to control wireless emanations, and using directional or beamforming antennas that reduce the likelihood that unintended receivers will be able to intercept signals. Prior to taking such mitigating actions, organizations can conduct periodic wireless surveys to understand the radio frequency profile of organizational systems as well as other systems that may be operating in the area.

Risk Assessment

CWE Categories

References

• NIST SP 800-53 Rev 5 - AC-18(5)
• 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 (PE-19) reviewed