CM-7(5)_authorized-software-allow-by-exception

CM-7(5) Authorized Software — Allow-by-exception

Enhancement of: CM-7

High-Level Description

Family: Configuration Management (CM) Framework: NIST SP 800-53 Rev 5

Authorized software programs can be limited to specific versions or from a specific source. To facilitate a comprehensive authorized software process and increase the strength of protection for attacks that bypass application level authorized software, software programs may be decomposed into and monitored at different levels of detail. These levels include applications, application programming interfaces, application modules, scripts, system processes, system services, kernel functions, registries, drivers, and dynamic link libraries. The concept of permitting the execution of authorized software may also be applied to user actions, system ports and protocols, IP addresses/ranges, websites, and MAC addresses. Organizations consider verifying the integrity of authorized software programs using digital signatures, cryptographic checksums, or hash functions. Verification of authorized software can occur either prior to execution or at system startup. The identification of authorized URLs for websites is addressed in CA-3(5) and SC-7.

What to Check

• Verify CM-7(5) Authorized Software — Allow-by-exception is documented in SSP
• Validate all 3 control requirements are implemented
• Confirm control is operating effectively
• Review evidence of continuous monitoring for CM-7(5)
• Verify enhancement builds upon base control CM-7

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for CM-7(5) 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 [organization-defined]; Employ a deny-all, permit-by-exception policy to allow the execution of authorized software programs on the system; and Review and update the list of authorized software programs [organization-defined].

Implementation Guidance

Authorized software programs can be limited to specific versions or from a specific source. To facilitate a comprehensive authorized software process and increase the strength of protection for attacks that bypass application level authorized software, software programs may be decomposed into and monitored at different levels of detail. These levels include applications, application programming interfaces, application modules, scripts, system processes, system services, kernel functions, registries, drivers, and dynamic link libraries. The concept of permitting the execution of authorized software may also be applied to user actions, system ports and protocols, IP addresses/ranges, websites, and MAC addresses. Organizations consider verifying the integrity of authorized software programs using digital signatures, cryptographic checksums, or hash functions. Verification of authorized software can occur either prior to execution or at system startup. The identification of authorized URLs for websites is addressed in CA-3(5) and SC-7.

Risk Assessment

CWE Categories

References

• NIST SP 800-53 Rev 5 - CM-7(5)
• 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 (CM-2, CM-6, CM-8, CM-10, PL-9) reviewed