MA-4_nonlocal-maintenance

MA-4 Nonlocal Maintenance

High-Level Description

Family: Maintenance (MA) Framework: NIST SP 800-53 Rev 5

Nonlocal maintenance and diagnostic activities are conducted by individuals who communicate through either an external or internal network. Local maintenance and diagnostic activities are carried out by individuals who are physically present at the system location and not communicating across a network connection. Authentication techniques used to establish nonlocal maintenance and diagnostic sessions reflect the network access requirements in IA-2 . Strong authentication requires authenticators that are resistant to replay attacks and employ multi-factor authentication. Strong authenticators include PKI where certificates are stored on a token protected by a password, passphrase, or biometric. Enforcing requirements in MA-4 is accomplished, in part, by other controls. SP 800-63B provides additional guidance on strong authentication and authenticators.

What to Check

• Verify MA-4 Nonlocal Maintenance is documented in SSP
• Validate all 5 control requirements are implemented
• Confirm control is operating effectively
• Review evidence of continuous monitoring for MA-4

How to Test

Step 1: Review Documentation

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

Approve and monitor nonlocal maintenance and diagnostic activities; Allow the use of nonlocal maintenance and diagnostic tools only as consistent with organizational policy and documented in the security plan for the system; Employ strong authentication in the establishment of nonlocal maintenance and diagnostic sessions; Maintain records for nonlocal maintenance and diagnostic activities; and Terminate session and network connections when nonlocal maintenance is completed.

Implementation Guidance

Nonlocal maintenance and diagnostic activities are conducted by individuals who communicate through either an external or internal network. Local maintenance and diagnostic activities are carried out by individuals who are physically present at the system location and not communicating across a network connection. Authentication techniques used to establish nonlocal maintenance and diagnostic sessions reflect the network access requirements in IA-2 . Strong authentication requires authenticators that are resistant to replay attacks and employ multi-factor authentication. Strong authenticators include PKI where certificates are stored on a token protected by a password, passphrase, or biometric. Enforcing requirements in MA-4 is accomplished, in part, by other controls. SP 800-63B provides additional guidance on strong authentication and authenticators.

Risk Assessment

CWE Categories

References

• NIST SP 800-53 Rev 5 - MA-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 (AC-2, AC-3, AC-6, AC-17, AU-2) reviewed