Access Control 3.1.6 (3.1.6)

What Is This CMMC Control?

Organizations must ensure that users operate with standard, non-privileged accounts when performing routine business functions that do not require elevated permissions. Privileged accounts (like administrator or root accounts) should only be used when performing security-related or administrative tasks that specifically require those elevated permissions. This reduces the risk of accidental or malicious damage to systems and data by limiting the exposure window when operating with elevated privileges.

Control Intent

Minimize the attack surface and reduce the potential impact of compromised credentials by ensuring users operate with the minimum necessary privileges for their current task. This control prevents the unnecessary use of privileged accounts for routine operations, thereby limiting opportunities for privilege escalation, malware execution with elevated permissions, and accidental system modifications.

Who This Control Applies To

• •All users who have been granted privileged accounts or roles within the CUI environment
• •All systems and applications within the CMMC assessment boundary that support user authentication and authorization
• •Workstations, servers, network devices, and cloud services where users perform both privileged and non-privileged functions
• •Service accounts and automated processes that may operate with elevated privileges

Expected Evidence

Organizations should maintain documentation and evidence demonstrating compliance with this control. This may include policy documentation, configuration records, audit logs, access reviews, and other relevant artifacts that show how the control is implemented and maintained.

Plan of Action & Milestones (POA&M)

If separate privileged and non-privileged accounts do not exist, create a POA&M with milestones for provisioning separate accounts for all administrative users, starting with the highest-risk privileged accounts (e.g., domain administrators). If privileged accounts are being used for routine functions, create a POA&M to implement technical controls (e.g., application whitelisting, network restrictions) that prevent privileged accounts from accessing email, web browsers, and other non-administrative applications. If no monitoring exists to detect violations, create a POA&M to implement logging and alerting for privileged account usage, with milestones for deploying monitoring tools and establishing baseline acceptable use patterns. If users are not trained on the requirement, create a POA&M to develop and deliver training on privilege separation, with milestones for training completion and policy acknowledgment. If implementing Privileged Access Workstations, create a POA&M with milestones for procuring hardware, configuring and hardening PAWs, and transitioning administrative users to the new workflow. If implementing a privileged access management solution, create a POA&M with milestones for vendor selection, deployment, integration with existing systems, and user onboarding. Ensure POA&M milestones are realistic and account for the operational impact of changing how administrative users perform their work. Consider phased implementation starting with the most critical systems or highest-risk privileged accounts. Include compensating controls in the POA&M if full implementation will take significant time, such as increased monitoring or manual review of privileged account activity.