SC-41_port-and-io-device-access

SC-41 Port and I/O Device Access

High-Level Description

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

Connection ports include Universal Serial Bus (USB), Thunderbolt, and Firewire (IEEE 1394). Input/output (I/O) devices include compact disc and digital versatile disc drives. Disabling or removing such connection ports and I/O devices helps prevent the exfiltration of information from systems and the introduction of malicious code from those ports or devices. Physically disabling or removing ports and/or devices is the stronger action.

What to Check

• Verify SC-41 Port and I/O Device Access is documented in SSP
• Confirm control is operating effectively
• Review evidence of continuous monitoring for SC-41

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for SC-41 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

[organization-defined] disable or remove [organization-defined] on the following systems or system components: [organization-defined].

Implementation Guidance

Connection ports include Universal Serial Bus (USB), Thunderbolt, and Firewire (IEEE 1394). Input/output (I/O) devices include compact disc and digital versatile disc drives. Disabling or removing such connection ports and I/O devices helps prevent the exfiltration of information from systems and the introduction of malicious code from those ports or devices. Physically disabling or removing ports and/or devices is the stronger action.

Risk Assessment

CWE Categories

References

• NIST SP 800-53 Rev 5 - SC-41
• 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-20, MP-7) reviewed