Benefits:

Reduced risk of unauthorized disclosure: By restricting access to authorized users only, the control minimizes the chance of sensitive CUI falling into the wrong hands, preventing potential breaches and protecting national security interests.

Enhanced accountability: Clear procedures for access control and record-keeping create a traceable audit trail, enabling identification of individuals who accessed CUI, facilitating investigations and improving overall accountability.

Improved compliance: Implementing this control demonstrates an organization's commitment to adhering to NIST 800-171 and other relevant security regulations, potentially easing compliance audits and reducing the risk of penalties.

Accountability:

Senior Management: Responsible for establishing clear policies and procedures regarding CUI access on system media, ensuring adequate resources are allocated for its implementation, and fostering a culture of information security awareness within the organization. They are accountable for oversight and ensuring effectiveness of implemented controls.

IT Security Team: Responsible for developing and implementing technical controls to limit access to CUI on system media. This includes user access controls, encryption, and logging mechanisms. They are also responsible for monitoring and auditing access attempts to detect and respond to potential security incidents.

System Owners: Responsible for understanding the CUI stored on their systems and identifying authorized users who require access to it on system media. They collaborate with the IT security team to implement appropriate access controls and ensure proper training for authorized users on secure handling of CUI.

Individual Users: Responsible for adhering to established policies and procedures regarding CUI access. This includes using strong passwords, avoiding unauthorized access attempts, and reporting any suspicious activity or suspected breaches.

Implementation:

Physical controls: Secure storage solutions like locked cabinets, controlled access media libraries, and conducting regular inventories ensure physical control over CUI media.

Logical controls: Implementing user access controls (passwords, multi-factor authentication) and permission-based access to CUI on the media further restricts access to authorized individuals.

Procedures and training: Establishing clear procedures for check-out/check-in of CUI media, user access requests, and proper disposal/sanitization practices is crucial. Additionally, training personnel on these procedures and the importance of CUI security strengthens the control's effectiveness.