Understanding NIST 800-171 Revision 3 Ghost Controls: What They Are and How to Address Them

In the realm of cybersecurity compliance, the term "ghost controls" has become increasingly relevant, particularly with the release of NIST 800-171 Revision 3. These ghost controls refer to the security controls that, while technically removed or "withdrawn" from the standard, still influence the compliance framework indirectly. Understanding and addressing these ghost controls is crucial for organizations aiming to achieve full compliance with NIST 800-171 Revision 3.

What Are Ghost Controls?

Ghost controls are essentially security requirements that have been officially withdrawn from the latest version of NIST 800-171 but are still relevant because their functions have been absorbed into other, more comprehensive controls. These controls may no longer exist as standalone requirements, but the need to address their objectives persists, making them "ghosts" in the compliance landscape.

For instance, Revision 3 of NIST 800-171 reduced the number of formal requirements from 110 to 97. This reduction was achieved by consolidating multiple controls into single, broader requirements. However, just because a control was removed does not mean its intent or the security it provided is no longer necessary​.

Why Ghost Controls Matter

Ghost controls are important because they represent areas where organizations could easily overlook critical security measures if they focus solely on the new, condensed list of requirements. These controls may not be explicitly listed, but they still need to be addressed to ensure that the overall security posture remains robust and that the organization truly complies with the spirit of NIST 800-171.

For example, a requirement related to insider threat awareness training may have been formally withdrawn, but its core aspects could be embedded within a more generalized security awareness control. If an organization fails to recognize this, they might inadvertently reduce their focus on insider threats, thereby exposing themselves to risk​.

How to Identify and Address Ghost Controls

1. Conduct a Detailed Review of Revisions: Start by carefully reviewing both the old and new versions of NIST 800-171. Identify which controls have been removed and understand where their elements have been absorbed into other requirements. This comparison will help you track down ghost controls that still need attention.

2. Cross-Reference with NIST 800-53: NIST 800-171 draws heavily from NIST 800-53, especially with the alignment seen in Revision 3. By cross-referencing the withdrawn controls with the corresponding controls in NIST 800-53, you can better understand how these requirements are still relevant​(

3. Maintain Comprehensive Documentation: Ensure that your documentation reflects not just the explicit requirements of NIST 800-171 Revision 3 but also the spirit of the withdrawn controls. This approach ensures that even if a control is not named, its purpose is still met through other means.

4. Regularly Update Security Practices: Cybersecurity is an evolving field, and what may have been a standalone requirement in the past could now be considered a baseline practice embedded in broader controls. Regularly updating your security practices to reflect the latest threats and compliance requirements is essential for addressing ghost controls effectively.

5. Engage with Compliance Experts: Given the complexity of tracking and addressing ghost controls, engaging with cybersecurity and compliance experts can provide valuable insights. These professionals can help ensure that your interpretation of the revised requirements covers all necessary aspects, including the ghosts of past controls.

Conclusion

Ghost controls in NIST 800-171 Revision 3 represent a subtle but significant challenge for organizations striving for compliance. By recognizing that these withdrawn controls still have a presence within the framework, and by taking steps to address them, organizations can ensure they meet both the letter and the spirit of the law. This proactive approach not only helps achieve compliance but also strengthens the overall cybersecurity posture, safeguarding sensitive data against evolving threats.

For more detailed guidance on NIST 800-171 Revision 3 and how to manage ghost controls, consider consulting the comprehensive resources provided by NIST and cybersecurity professionals​.