SC-45(2)_secondary-authoritative-time-source

SC-45(2) Secondary Authoritative Time Source

Enhancement of: SC-45

High-Level Description

Family: System and Communications Protection (SC) Framework: NIST SP 800-53 Rev 5

It may be necessary to employ geolocation information to determine that the secondary authoritative time source is in a different geographic region.

What to Check

• Verify SC-45(2) Secondary Authoritative Time Source is documented in SSP
• Validate all 2 control requirements are implemented
• Confirm control is operating effectively
• Review evidence of continuous monitoring for SC-45(2)
• Verify enhancement builds upon base control SC-45

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for SC-45(2) 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

Identify a secondary authoritative time source that is in a different geographic region than the primary authoritative time source; and Synchronize the internal system clocks to the secondary authoritative time source if the primary authoritative time source is unavailable.

Implementation Guidance

It may be necessary to employ geolocation information to determine that the secondary authoritative time source is in a different geographic region.

Risk Assessment

CWE Categories

References

• NIST SP 800-53 Rev 5 - SC-45(2)
• 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