What is NIST 800-171 Control 3.13.4?
Control 3.13.4 focuses on securing indirect data paths—places in a system where CUI could unintentionally be exposed, such as:
• Memory buffers
• Disk storage used by multiple applications
• Spoolers or cache files
• Shared virtual machines or containers
Your systems should prevent one user or process from accessing residual data left behind by another, especially if CUI is involved.
Why It Matters
Even if access controls are in place, data can leak through shared mechanisms:
• Leftover memory data after a process exits
• Print jobs stored in a shared queue
• Cache or swap space not cleared between sessions
Attackers can exploit these “side channels” to extract sensitive data without directly breaching user accounts.
How to Implement It
• Configure systems to clear memory, cache, or temporary files between users or processes
• Use access controls to restrict visibility into shared resources (e.g., print queues, logs)
• Isolate virtual environments (e.g., containers, VMs) with strong hypervisor or sandbox protections
• Disable unnecessary shared system features on CUI-handling systems
• Audit for cross-user access to shared resources
Common Mistakes
• Leaving print queues open to all users
• Failing to sanitize temp directories or shared file paths
• Using public or community-hosted virtual environments for CUI processing
How Cuick Trac Helps
Cuick Trac helps eliminate risk from shared resources by:
• Running CUI systems within a dedicated, pre-hardened enclave
• Enforcing strict memory and storage isolation policies
• Providing secure printing, logging, and temporary file handling configurations
• Offering guidance on CUI-compliant system configurations and data lifecycle management
With Cuick Trac, CUI exposure through system “leftovers” becomes a non-issue.
Final CTA
Don’t let sensitive data linger where it doesn’t belong.
Book a Cuick Trac demo and lock down the hidden paths where CUI could leak.
