As the cyber threat landscape becomes increasingly dominated by state-sponsored actors and advanced persistent threats, the DoD has taken critical steps to evolve its cybersecurity requirements for defense contractors. 

For contractors handling Controlled Unclassified Information and seeking to achieve CMMC Level 3, the NIST SP 800-172 Enhanced Security Requirements represent the most stringent technical and procedural benchmarks currently required in the DIB.

This article explores the practical implementation of NIST 800-172 controls, emphasizing advanced security capabilities, resilience engineering, and operational maturity necessary for high-trust environments.

 

Understanding the Move from NIST 800-171 to 800-172

NIST SP 800-171 establishes 110 baseline controls protecting CUI in non-federal systems. These controls form the foundation for CMMC Level 2. However, NIST 800-171 alone is insufficient against APTs, which are well-funded, patient, and capable of lateral movement and data exfiltration using stealthy techniques.

NIST 800-172 augments this baseline with 35 additional “enhanced” security requirements, distributed across three major families:

• Security Architecture and Engineering
• Cybersecurity Situational Awareness
• Cybersecurity Response

These controls are designed to counteract sophisticated tactics seen in advanced threat campaigns, such as living-off-the-land techniques, zero-day exploitation, and privilege escalation within trusted systems.

Achieving CMMC Level 3 requires organizations to comply with these controls and operationalize them through mature processes, skilled personnel, and infrastructure capable of enduring continuous threats.

 

Security Architecture and Engineering

One of the most misunderstood aspects of NIST 800-172 is its emphasis on security architecture as a strategy, rather than a collection of controls. Implementing the architectural controls in practice requires alignment with Zero Trust Architecture (ZTA), secure enclave design, and embedded assurance.

 

Isolation and Segmentation at the Enforcement Plane

NIST 800-172 mandates system segmentation to isolate CUI processing systems from other business systems. This isn’t just VLAN separation;  it requires enforcement at the data plane, ideally through:

• Application-layer segmentation using software-defined parameters
• User and device identity-bound access control via dynamic policy enforcement
• No implicit trust between segments, validated with continual authentication

Additionally, memory-safe languages and hardened OS kernels should be used to minimize the attack surface at the application level.

 

Software Integrity Verification Using Root of Trust

Control 3.14.1e in NIST SP 800-172 emphasizes the need to verify the integrity of security-critical or essential software using roots of trust or cryptographic signatures. This requirement builds upon the principles of trusted computing and ensures that sensitive components like bootloaders, kernel modules, and authentication systems have not been tampered with.

In practical terms, organizations should implement:

• Secure boot and measured boot chains that leverage hardware-based roots of trust to verify digital signatures at each stage of system initialization.
• Firmware validation using tools that interface with manufacturer-provided cryptographic manifests or device attestation services.
• Continuous attestation mechanisms, where possible, that confirm system state integrity across reboots, especially in virtualized or cloud-hosted workloads.

This control does not mandate runtime verification. Instead, it emphasizes pre-execution verification and cryptographically bound methods to ensure that only known-good code is executed on mission-critical systems.

 

Situational Awareness in Advanced CMMC Compliance

The controls in this domain require visibility and a contextual, real-time understanding of what adversaries are doing inside the network. As such, it leans heavily on concepts like analytical and behavioral analysis, proactive threat hunting, and response capabilities. 

Behavioral Analytics and Detection Engineering

Control 3.14.7e requires verification of software correctness using organization-defined techniques, potentially including formal methods, runtime analysis, or rigorous testing frameworks.

Behavior-based monitoring is especially valuable when integrated with:

• User and Entity Behavior Analytics (UEBA) that baseline regular activity.
• Threat intelligence feeds mapped to MITRE ATT&CK.
• Detection-as-code pipelines to continuously adapt SIEM and XDR systems.

 

Threat Hunting 

Control 3.14.6e recommends proactive threat hunting, a formal function with resources, tools, and a feedback loop into detection systems.

Implementation includes:

• Hypothesis-driven hunts based on adversary threats.
• Use of enriched telemetry across endpoints, networks, and cloud environments.
• Integration with red/purple team exercises to refine detection coverage.

 

Cybersecurity Response

Controls in this family shift the paradigm from incident reaction to cyber resilience and adversarial engagement.

 

Deception Technologies and Synthetic Assets

Control 3.13.5e encourages the use of deception techniques to mislead or delay adversaries. Advanced implementations include:

• Canary tokens and decoy credentials that alert upon use.
• Synthetic hosts or services that mimic production but serve no real function.
• Endpoint-level traps that trigger on unauthorized enumeration or manipulation.

These capabilities buy defenders time and increase attacker workload without relying solely on detection.

 

Dynamic Containment and Automated Response

Control 3.14.4e calls for automatically disabling or restricting access based on threat indicators. Effective strategies include:

• SOAR playbooks that quarantine compromised hosts or revoke credentials.
• Policy-driven network segmentation adjustments based on alert context.
• Safe fallback modes that preserve operations during active containment.

Organizations must ensure these actions are tested and not unintentionally disrupt mission-essential functions.

 

Governance, Risk, and Continuous Validation

The final ingredient in implementing NIST 800-172 is continuous control evaluation and risk governance.

 

Security Control Validation

Rather than rely solely on static assessments, organizations should implement:

• Breach and Attack Simulation (BAS) platforms.
• Red team exercises mapped directly to 800-172 controls.
• Automated compliance tracking integrated with SSP and POA&M documentation and reporting.

Insider Threat Program Development

Control 3.1.2e includes training employees to notice potential threats, including those from inside the organization. A mature program includes:

• Privileged access monitoring.
• Cross-correlation of identity, behavioral, and physical data.
• Behavioral profiling with regular reassessment based on role and environment.

 

Navigate the Highest Levels of CMMC with Continuum GRC

The practical implementation of NIST 800-172 for CMMC Level 3 is achievable, but only through architectural discipline, operational maturity, and investment in people, processes, and technology. Organizations that succeed will pass certification and stand resilient against the world’s most capable adversaries.

Continuum GRC is a cloud platform that stays ahead of the curve, including support for all certifications (along with our sister company and assessors, Lazarus Alliance). 

• FedRAMP
• StateRAMP
• NIST 800-53
• FARS NIST 800-171 & 172
• CMMC
• SOC 1 & SOC 2
• HIPAA
• PCI DSS 4.0
• IRS 1075 & 4812
• COSO SOX
• ISO 27001 + other ISO standards
• NIAP Common Criteria
• And dozens more!

We are the only FedRAMP and StateRAMP-authorized compliance and risk management solution worldwide.

Continuum GRC is a proactive cybersecurity® and the only FedRAMP and StateRAMP-authorized cybersecurity audit platform worldwide. Call 1-888-896-6207 to discuss your organization’s cybersecurity needs and learn how we can help protect its systems and ensure compliance.