NIST 800-53 REV 5 • ACCESS CONTROL
AC-6 — Least Privilege
Employ the principle of least privilege, allowing only authorized accesses for users (or processes acting on behalf of users) that are necessary to accomplish assigned organizational tasks.
Supplemental Guidance
Organizations employ least privilege for specific duties and systems. The principle of least privilege is also applied to system processes, ensuring that the processes have access to systems and operate at privilege levels no higher than necessary to accomplish organizational missions or business functions. Organizations consider the creation of additional processes, roles, and accounts as necessary to achieve least privilege. Organizations apply least privilege to the development, implementation, and operation of organizational systems.
Practitioner Notes
Least privilege means everyone gets only the minimum access they need to do their job — nothing more. If you do not need admin rights, you should not have them. If you only need read access, you should not have write access.
Example 1: In Active Directory, remove all standard users from the local Administrators group on their workstations. Use a GPO at Computer Configuration → Preferences → Control Panel Settings → Local Users and Groups to enforce this. If someone needs elevated access for a specific task, use a PAM tool for temporary elevation.
Example 2: In Azure, assign the Reader role instead of Contributor for users who only need to view resources. Scope role assignments to the specific resource group, not the entire subscription. Review role assignments quarterly using Azure AD → Access Reviews.