RMF Control AC-10: Concurrent Session Control is a cybersecurity control that helps to protect information systems by limiting the number of concurrent sessions that a user can have. This control is important because it can help to prevent unauthorized access to information systems and data.

Concurrent Session Control Requirements

The RMF Control AC-10: Concurrent Session Control requirements are specified in NIST Special Publication 800-53, Revision 5. The requirements state that the organization must:

  • Limit the number of concurrent sessions for each account or account type to a specific number;
  • Monitor and audit concurrent sessions to identify and respond to suspicious activity; and
  • Establish an incident response plan to address unauthorized concurrent sessions.

Concurrent Session Control Best Practices

In addition to the RMF Control AC-10: Concurrent Session Control requirements, there are a number of best practices that organizations can follow to improve their concurrent session control posture. These best practices include:

  • Limiting the number of concurrent sessions to a low number (e.g., 2).
  • Monitoring and auditing concurrent sessions for suspicious activity, such as concurrent sessions from different locations or at unusual times.
  • Establishing an incident response plan to address unauthorized concurrent sessions. This plan should include steps to disable unauthorized sessions and investigate the cause of the unauthorized access.
  • Educating users on the importance of concurrent session control and how to avoid creating multiple concurrent sessions.

Benefits of Concurrent Session Control

Concurrent session control can provide a number of benefits to organizations, including:

  • Improved security posture: Concurrent session control can help to prevent unauthorized access to information systems and data.
  • Reduced risk of data breaches: Concurrent session control can help to reduce the risk of data breaches by detecting unauthorized access early.
  • Increased user awareness: Concurrent session control can help to increase user awareness of security threats and how to protect their accounts.
  • Improved compliance: Concurrent session control can help organizations to comply with a variety of security regulations.

How to Implement Concurrent Session Control

There are a number of ways to implement concurrent session control. One common approach is to use a security information and event management (SIEM) system. SIEM systems can collect and analyze log data from a variety of sources, including information systems, network devices, and security appliances. This data can then be used to identify and monitor concurrent sessions.

Another approach to implementing concurrent session control is to use a cloud-based service. There are a number of cloud-based services that offer concurrent session control capabilities. These services can be relatively easy to implement and use.

Example of Concurrent Session Control

One example of concurrent session control is when a user is automatically logged out of their account when they try to log in from a different location. This prevents the user from having multiple concurrent sessions.

Another example of concurrent session control is when a user is notified when they have more than a certain number of concurrent sessions. This notification can help the user to identify and respond to unauthorized concurrent sessions.

Conclusion

RMF Control AC-10: Concurrent Session Control is an important cybersecurity control that helps to protect information systems by limiting the number of concurrent sessions that a user can have. By following the RMF Control AC-10: Concurrent Session Control requirements and best practices, organizations can help to improve their security posture, reduce the risk of data breaches, increase user awareness, and improve compliance.

Additional Tips for Implementing and Enforcing Concurrent Session Control

  • Use a centralized authentication system to manage user accounts and concurrent sessions.
  • Implement a multi-factor authentication (MFA) solution to add an extra layer of security to the logon process.
  • Use a risk-based approach to concurrent session control. For example, you may want to limit the number of concurrent sessions for all users, or you may only want to limit the number of concurrent sessions for users with access to sensitive data.
  • Educate users on the importance of concurrent session control and how to avoid creating multiple concurrent sessions.

By following these tips, organizations can help to ensure that their information systems are protected from unauthorized access and misuse.