IA-8(2)_acceptance-of-external-authenticators
DevOps & SecurityAccept only external authenticators that are NIST-compliant;
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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
| Tool | Purpose | Usage |
|---|---|---|
| cloud-audit-mcp | Check authentication settings | cloud_audit_iam_policies |
| hackbrowser-mcp | Test authentication mechanisms | browser_auth_test |
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
| Finding | Severity | Impact |
|---|---|---|
| IA-8(2) Acceptance of External Authenticators not implemented | High | Identification and Authentication |
| IA-8(2) partially implemented | Medium | Incomplete Identification and Authentication |
CWE Categories
| CWE ID | Title |
|---|---|
| CWE-287 | Improper Authentication |
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