Mapped to NIST 800-171 Requirement: 3.1.3
CMMC Assessment Objective: AC.L2-3.1.3[d]
What This Objective Means
This objective goes one level deeper than verifying system configuration—it asks the assessor to identify the specific tools, technologies, or controls that are actively enforcing data flow rules for CUI.
It’s not just “Is CUI controlled?”
It’s: What enforces that control, and how?
Examples of enforcement mechanisms include:
• Firewalls
• Virtual LANs (VLANs)
• Endpoint protection
• Secure email gateways
• DLP (Data Loss Prevention) tools
• Application permissions that restrict where CUI can be shared or exported
Why It Matters
Defining data flow is step one. Enforcing it through mechanisms that work as intended is what prevents:
• Accidental exposure
• Data exfiltration
• Transmission of CUI to unauthorized or insecure systems
Clear, documented mechanisms give auditors confidence—and give your security team clarity.
How to Implement It
• Identify all enforcement points for CUI movement:
◦ Network: Firewalls, proxies, DNS filtering, segmentation
◦ Endpoint: DLP, EDR, USB blocking, secure print
◦ Application: Export restrictions, access control lists
• Document each mechanism and how it contributes to data flow enforcement
• Map enforcement mechanisms to system configurations and policies
• Test enforcement mechanisms to confirm they’re operational
Evidence the Assessor Will Look For
• Lists or diagrams of CUI enforcement tools and where they are deployed
• Screenshots or exports of:
◦ Firewall rule sets
◦ DLP policy settings
◦ Endpoint device restrictions
◦ Application-level access controls
• Documentation showing how each mechanism is configured to protect CUI
• Test results or logs confirming active enforcement
Common Gaps
• No clear understanding of which tools enforce CUI flow
• Relying on manual controls without technical enforcement
• Enforcement mechanisms disabled or misconfigured
How Cuick Trac Helps
Cuick Trac ensures enforcement mechanisms are:
• Built into the system architecture from day one
• Configured to restrict CUI movement within and outside the enclave
• Integrated with logging and alerting to catch any attempted violations
• Fully documented and exportable for assessment and audit readiness
With Cuick Trac, the question isn’t whether enforcement exists—it’s where, how, and how well.
Final CTA
Policies define your intentions. Enforcement mechanisms prove them.
Schedule a Cuick Trac demo and lock down your CUI flows with confidence.