RMF Control AC-25: Reference Monitor is a cybersecurity control that helps to protect information systems by ensuring that all access to information systems and resources is monitored and controlled. This control is important because it can help to prevent unauthorized access to information systems and resources, and to detect and respond to unauthorized access attempts.

Reference Monitor Requirements

The RMF Control AC-25: Reference Monitor requirements are specified in NIST Special Publication 800-53, Revision 5. The requirements state that the organization must:

  • Implement a reference monitor that is tamperproof and cannot be bypassed;
  • Implement a reference monitor that is able to mediate all access to information systems and resources;
  • Monitor and audit all access to information systems and resources; and
  • Protect the confidentiality, integrity, and availability of the reference monitor.

Reference Monitor Best Practices

In addition to the RMF Control AC-25: Reference Monitor requirements, there are a number of best practices that organizations can follow to improve their reference monitor posture. These best practices include:

  • Using a centralized system to manage reference monitor policies and procedures;
  • Implementing a risk-based approach to reference monitor implementation;
  • Monitoring and auditing reference monitor activity to identify and respond to suspicious activity;
  • Educating users on the importance of reference monitor security and how to protect the reference monitor from tampering.

Benefits of Reference Monitor

Reference monitors can provide a number of benefits to organizations, including:

  • Improved security posture: Reference monitors can help to improve the organization’s security posture by reducing the risk of unauthorized access to information systems and resources.
  • Reduced risk of data breaches: Reference monitors can help to reduce the risk of data breaches by making it more difficult for unauthorized users to access sensitive data.
  • Increased compliance: Reference monitors can help organizations to comply with a variety of security regulations, such as the General Data Protection Regulation (GDPR).

How to Implement Reference Monitor

There are a number of ways to implement reference monitors. One common approach is to use an operating system security module (OSSM). OSSMs are security modules that are built into operating systems and that provide reference monitor functionality.

Another approach to implementing reference monitors is to use a hypervisor-based security monitor (HSM). HSMs are security monitors that reside in a hypervisor and that provide reference monitor functionality for all virtual machines that are running on the hypervisor.

Example of Reference Monitor

One example of a reference monitor is an operating system security module (OSSM). OSSMs are security modules that are built into operating systems and that provide reference monitor functionality. OSSMs typically provide a variety of security features, such as access control, auditing, and intrusion detection.

Another example of a reference monitor is a hypervisor-based security monitor (HSM). HSMs are security monitors that reside in a hypervisor and that provide reference monitor functionality for all virtual machines that are running on the hypervisor. HSMs typically provide a variety of security features, such as access control, auditing, and intrusion detection.

Conclusion

RMF Control AC-25: Reference Monitor is an important cybersecurity control that helps to protect information systems by ensuring that all access to information systems and resources is monitored and controlled. By following the RMF Control AC-25: Reference Monitor requirements and best practices, organizations can help to improve their security posture, reduce the risk of data breaches, and increase compliance.

Additional Tips for Implementing and Enforcing Reference Monitor

  • Use a centralized system to manage reference monitor policies and procedures. This will help to ensure that reference monitor is implemented and enforced consistently across the organization.
  • Implement a risk-based approach to reference monitor implementation. This will help to ensure that reference monitor efforts are focused on the areas of greatest risk.
  • Monitor and audit reference monitor activity to identify and respond to suspicious activity. This can be done using a variety of tools and techniques, such as security information and event management (SIEM) solutions and intrusion detection systems (IDS).
  • Educate users on the importance of reference monitor security and how to protect the reference monitor from tampering. This can be done through training programs, documentation, and other resources.

By following these tips, organizations can help to ensure that their reference monitor is implemented and enforced effectively.