Privileged access is where policy language most quickly collides with operational convenience. An engineer needs to install a driver, the MSP needs emergency access, a domain administrator needs to troubleshoot identity, and a cloud owner needs to change tenant-wide settings. CMMC evidence has to show how those powerful actions are limited, approved, and attributable.
Least privilege under CMMC is more than removing local administrator from ordinary employees. NIST SP 800-171 Rev. 2 requirement 3.1.5 calls for the principle of least privilege, including for specific security functions and privileged accounts. Requirements 3.1.6 and 3.1.7 then push the design further: use non-privileged accounts or roles for nonsecurity functions, prevent non-privileged users from executing privileged functions, and capture execution of privileged functions in audit logs.
That trio creates a practical administrative model. People who need elevated rights should receive only the rights needed for defined tasks, use ordinary identities for ordinary work, elevate or switch to privileged roles for administration, and leave an audit trail that shows who performed the privileged action. A shared 'Administrator' credential used for email, web browsing, and server changes works against all three ideas.
A mature design separates the account used to read email and browse the web from the identity used to change security-sensitive configuration, then limits where the privileged identity can log in and how long elevated access persists.
Define privilege by capability, not by job title
Start with the actions that can change security or system operation: create accounts, grant access, change firewall rules, disable security tools, alter logging, restore backups, modify tenant policies, install software, change encryption settings, or administer the systems that store CUI. An employee called 'IT Manager' may need only some of those powers; a vendor engineer may temporarily need one of them.
Map those capabilities to platform roles and groups. Avoid broad roles such as Global Administrator or Domain Admin when a narrower role performs the task. Where the platform supports just-in-time or time-limited elevation, use it to reduce standing privilege. Where it does not, create named administrative groups aligned to real duties.
Document why each privilege exists. A short access request that identifies the system, role, business reason, approver, start date, and review date produces much stronger evidence than a spreadsheet created immediately before assessment.
Separate daily work from privileged work
Requirement 3.1.6 supports using non-privileged accounts or roles when accessing nonsecurity functions. That means administrators should not browse the web, read routine email, create documents, or perform ordinary collaboration with the same elevated identity they use to administer the CUI environment.
A practical small-business pattern is an ordinary user identity plus a separate privileged identity or an elevation mechanism. The privileged identity receives MFA and the administrative roles; the ordinary identity receives the user's collaboration and business access. This reduces the chance that phishing or a malicious document immediately obtains administrative capability.
Make the separation visible in logs and account naming. The assessor should be able to identify which account represents ordinary user activity and which represents administrative action. If one human has several privileged identities, tie them back to the same named owner in the account register.
Prevent unauthorized execution, not just unauthorized login
Requirement 3.1.7 focuses on privileged functions. A user may be authenticated to a system but should still be prevented from executing functions outside the assigned role. Test the control by attempting a representative administrative action with a normal user account and confirming the action is blocked.
Review local admin groups, application roles, sudoers files, cloud IAM roles, database privileges, device-management roles, and security-console permissions. Privilege can accumulate outside the primary directory. A quarterly review of one identity platform will miss administrator rights embedded in appliances and applications.
Restrict who can change the access-control mechanism itself. If every help desk technician can add themselves to the highest-privilege group without approval, the role model is not meaningfully enforced. Use separation of duties, approval, or protected administrator groups where appropriate to the size of the organization.
Treat vendor and MSP administrator access as part of the same privilege model. A support engineer who enters through a remote-management tool, cloud delegated-admin relationship, or temporary vendor account can perform privileged functions even though the person is not on the contractor's payroll. Require named access where the platform allows it, approve the scope and duration, remove access when the work ends, and retain enough logging to tie the administrative session to the external individual. This closes a common gap where internal administrators are tightly controlled but a vendor retains broad standing rights outside the normal review process.
Make privileged activity traceable in audit logs
NIST SP 800-171 Rev. 2 explicitly requires capturing the execution of privileged functions in audit logs under 3.1.7. Configure systems so administrative changes are attributable to an individual identity and produce logs that record the relevant action, target, time, and result. This connects least privilege to the Audit and Accountability family.
Shared admin accounts weaken that traceability. If a legacy system requires a common account, consider a controlled access broker, privileged-session management, check-out process, or other mechanism that can reliably bind the human user to the session. The evidence needs to let the organization answer 'who performed this privileged action?' without guessing from a shift schedule.
Send important administrative logs to a location users cannot casually erase. An administrator whose actions are being audited should not have unrestricted ability to delete the only copy of the log that records those actions.
Review privilege as a lifecycle, not an annual cleanup
Privilege should change when roles change. Integrate administrative access with onboarding, transfer, leave, and termination procedures. Temporary project rights need an expiration date or review trigger. Vendor access should end when the maintenance window or support relationship ends.
Use periodic reviews to compare assigned privilege with current responsibility. The reviewer should see the role, owner, last use where available, business justification, and approving manager. Remove dormant accounts and privileges that were granted for completed migrations or troubleshooting events.
Review break-glass accounts separately. They may be intentionally powerful, but that makes credential storage, access approval, monitoring, and post-use review especially important. An emergency account that appears in normal daily logs is a sign the access model is being bypassed.
Design break-glass access before the emergency
Emergency accounts should solve a defined failure mode, not become permanent shortcuts around normal controls. Document when the account may be used, who can authorize use, how credentials or keys are protected, what monitoring applies, and how access is reviewed after the event.
Test the path while the environment is healthy. A sealed credential that no one can retrieve, an account disabled by an identity policy, or an emergency login that bypasses all logging is not a reliable recovery mechanism. The test record should show both successful emergency access and the review/rotation steps that follow.
- Trigger for emergency use
- Named authorization path
- Credential/key custody
- Enhanced logging and alerting
- Post-use review and credential rotation
Build an assessor-ready privilege package
Keep the package concise: privileged-account register, role definitions, sample approvals, MFA enforcement, technical group or role exports, evidence that ordinary accounts cannot execute privileged functions, and sample administrative logs. Link these artifacts to the SSP implementation for 3.1.5 through 3.1.7 rather than storing them in separate unlabeled folders.
During an internal test, select one administrator and trace the complete path. Show the ordinary account, privileged account or elevation method, assigned role, approval, MFA, a recent privileged action, and the resulting log. Then select one normal user and demonstrate that the same privileged action is denied.
That two-user test catches most structural problems quickly. If the organization cannot explain why a privilege exists or cannot tie an administrative event to a person, fix the identity model before producing more policy language.
A short working check
- ✓Inventory privileged functions across systems and applications
- ✓Assign the narrowest practical roles
- ✓Separate ordinary and privileged user activity
- ✓Require appropriate MFA on privileged access paths
- ✓Prevent normal users from executing privileged functions
- ✓Log privileged execution with individual attribution
- ✓Review and remove stale or temporary privileges
Common questions
Is removing local admin from users enough for least privilege?
No. Least privilege also applies to privileged accounts, security functions, cloud roles, applications, network devices, and other administrative capabilities.
Why are logs part of least privilege?
Requirement 3.1.7 specifically calls for capturing execution of privileged functions in audit logs so the organization can trace and review administrative activity.
Official sources used for this guide
Open the primary source before making a contract-specific decision. Regulations and program implementation can change.
