Meeting the Compliance Framework requirement to enforce "authorized functions only" (FAR 52.204-21 / CMMC 2.0 Level 1 - AC.L1-B.1.II) is as much about training and proof-of-practice as it is about technical controls — this post gives concrete exercises, tools, and small-business scenarios to train admins and users so you can demonstrate effective implementation to auditors.
Understanding the control in practice
The core objective of this control in the Compliance Framework context is to ensure that only authorized individuals and processes can perform specific functions on systems that process controlled unclassified information (CUI) or other regulated data. Practically, that means implementing least privilege, role-based access controls (RBAC), separation of duties, and technical enforcement (ACLs, IAM policies, sudoers, group membership), and then proving through exercises and evidence that those mechanisms work and that staff know how to use them properly.
Designing practical exercises
Tabletop and role-play exercises
Start with low-cost, low-risk tabletop exercises for both admins and end users. Example: simulate a request from a contractor for privileged access to a dev server. Walk through the approval workflow (ticket creation, manager approval, and temporary access grant). Have participants explain why permanent escalation is inappropriate and document the expected steps. Record minutes, attendee lists, and the decision trail — auditors will accept these artifacts as evidence of training and process understanding.
Hands-on technical labs
Run short, focused labs that mirror your production tech stack. For Windows Active Directory environments, have admins add and remove users from AD groups using PowerShell: Add-ADGroupMember -Identity "CUI_Readers" -Members "jlee". For Linux sysadmins, practice creating scoped sudo policies in /etc/sudoers.d/ to allow specific commands: e.g., a file that contains "%it_admins ALL=(ALL) /usr/bin/systemctl, /usr/bin/journalctl" to limit elevated actions. For cloud environments, create a throwaway AWS account and exercise IAM policies — craft a policy that allows s3:GetObject for a specific bucket and test denied attempts to write. Capture screenshots and CloudTrail/SIEM logs of both allowed and denied operations as evidence that the system enforces function-level authorization.
Access review, recertification, and revocation drills
Schedule periodic access review exercises where managers receive a list of their direct reports' permissions and must attest to each. Use your ticketing system (ServiceNow, Jira) to simulate access revocation requests and time-boxed Just-In-Time (JIT) elevation — e.g., grant temporary sudo for two hours via PAM (BeyondTrust, CyberArk) or Azure AD Privileged Identity Management and then validate automatic expiry. Maintain logs of the revocation process and time stamps; auditors look for evidence that access changes were executed and enforced.
Small-business real-world scenario
Imagine a 25-person engineering firm holding a DoD subcontract with limited CUI. Practical steps: inventory systems holding CUI, map roles (engineer, project manager, admin), implement AD or cloud groups like "CUI_Viewers" and "CUI_Editors," and restrict editor functions to a small admin group. Run quarterly exercises where an engineer requests elevated access to a CUI repository — the request must flow through a documented approval chain and be granted only via a time-limited group membership change. Document the request, approval, ticket ID, time-limited AD change, and the log showing the engineer's subsequent access; these artifacts satisfy both training and evidence requirements in a small-business audit.
Compliance tips and best practices
Keep exercises short, repeatable, and measurable. Use a checklist for each exercise: objective, participants, steps, expected result, actual result, artifacts collected (screenshots, logs, ticket numbers), and lessons learned. Automate evidence collection where possible: enable audit logging (Windows Event Forwarding, CloudTrail, syslog), export activity to a SIEM, and attach relevant log extracts to the exercise report. Maintain a training matrix that maps exercises to control objectives in the Compliance Framework so you can quickly show coverage during assessments.
Technical specifics to implement and test
Key technical controls to implement and include in exercises: RBAC groups with documented membership rules, MFA on all accounts that can perform privileged functions, PAM or JIT solutions for temporary elevation, ACLs on file shares and objects, and logging/alerting for denied attempts. For example, enable Windows GPO to restrict local admin rights, configure an IAM policy in AWS that denies s3:PutObject for CUI buckets to non-approved roles, and validate via test accounts that denial is enforced. Collect logs: sample entries showing "Access denied" plus the principal, timestamp, resource, and reason are golden evidence.
Risks of not implementing these exercises
Failure to train and verify authorized-function enforcement increases the risk of unauthorized disclosure of CUI, lateral movement by threat actors using misconfigured privileged accounts, contract penalties, and loss of future DoD work. From a compliance perspective, you may face audit findings or requirement failures because controls may exist only in theory — auditors expect to see that staff both understand procedures and that systems demonstrably block unauthorized functions.
Summary
To meet FAR 52.204-21 / CMMC 2.0 Level 1 AC.L1-B.1.II under the Compliance Framework, combine technical enforcement (RBAC, ACLs, PAM, IAM) with repeatable, documented exercises: tabletop role-play, hands-on labs, access review drills, and revocation workflows. For small businesses, keep exercises pragmatic, automate evidence capture, and map artifacts to control objectives so you can show auditors both competence and effective enforcement — preventing unauthorized functions from becoming compliance and security incidents.
