IA-8(2)_acceptance-of-external-authenticators

IA-8(2) Acceptance of External Authenticators

Enhancement of: IA-8

High-Level Description

Family: Identification and Authentication (IA) Framework: NIST SP 800-53 Rev 5

Acceptance of only NIST-compliant external authenticators applies to organizational systems that are accessible to the public (e.g., public-facing websites). External authenticators are issued by nonfederal government entities and are compliant with SP 800-63B . Approved external authenticators meet or exceed the minimum Federal Government-wide technical, security, privacy, and organizational maturity requirements. Meeting or exceeding Federal requirements allows Federal Government relying parties to trust external authenticators in connection with an authentication transaction at a specified authenticator assurance level.

What to Check

• Verify IA-8(2) Acceptance of External Authenticators is documented in SSP
• Validate all 2 control requirements are implemented
• Confirm control is operating effectively
• Review evidence of continuous monitoring for IA-8(2)
• Verify enhancement builds upon base control IA-8

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for IA-8(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

Accept only external authenticators that are NIST-compliant; and Document and maintain a list of accepted external authenticators.

Implementation Guidance

Acceptance of only NIST-compliant external authenticators applies to organizational systems that are accessible to the public (e.g., public-facing websites). External authenticators are issued by nonfederal government entities and are compliant with SP 800-63B . Approved external authenticators meet or exceed the minimum Federal Government-wide technical, security, privacy, and organizational maturity requirements. Meeting or exceeding Federal requirements allows Federal Government relying parties to trust external authenticators in connection with an authentication transaction at a specified authenticator assurance level.

Risk Assessment

CWE Categories

References

• NIST SP 800-53 Rev 5 - IA-8(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