Changed CMMC-CCP Exam Questions

Understanding the Principle of Least Functionality in the CM Domain

TheConfiguration Management (CM) domainin CMMC 2.0 focuses on maintaining the security and integrity of an organization’s systems through controlled configurations and restrictions on system capabilities.

The principle ofLeast Functionalityrefers to limiting a system’s features, services, and applications to only those necessary for its intended purpose. This principle reduces the attack surface by minimizing unnecessary components that could be exploited by attackers.

Justification for the Correct Answer: Least Functionality (C)

CMMC Practice CM.L2-3.4.6 (Use Least Functionality)explicitly states:

"Employ the principle of least functionality by configuring organizational systems to provide only essential capabilities."

Thegoalis to prevent unauthorized or unnecessary applications, services, and ports from running on the system.

Examples of Implementation:

Disabling unnecessary services, such as remote desktop access if not required.

Restricting software installation to approved applications.

Blocking unused network ports and protocols.

Why Other Options Are Incorrect

A. Least Privilege

This principle (associated with Access Control) ensures that users and processes have only the minimum level of access necessary to perform their jobs.

It is relevant to CMMC PracticeAC.L2-3.1.5 (Least Privilege)but does not define system capabilities.

B. Essential Concern

There is no officially recognized cybersecurity principle called "Essential Concern" in CMMC, NIST, or related frameworks.

D. Separation of Duties

This principle (covered under CMMCAC.L2-3.1.4) ensures that no single individual has unchecked control over critical functions, reducing the risk of fraud or abuse.

While important for security, it does not define essential system capabilities.

Official CMMC and NIST References

CMMC 2.0 Level 2 Assessment Guide – Configuration Management (CM) Domain

CM.L2-3.4.6 mandatesleast functionalityto enhance security by removing unnecessary features.

NIST SP 800-171 (which CMMC is based on) – Requirement 3.4.6

States:"Limit system functionality to only the essential capabilities required for organizational missions or business functions."

NIST SP 800-53 – Control CM-7 (Least Functionality)

Provides detailed recommendations on configuring systems to operate with only necessary features.

Conclusion

Theprinciple of Least Functionality (C)is the basis for defining essential system capabilities in theConfiguration Management (CM) domainof CMMC 2.0. By applying this principle, organizations reduce security risks by ensuring that only the necessary functions, services, and applications are enabled.

Understanding SI.L1-3.14.2: Provide Protection from Malicious Code

The CMMC Level 1 practiceSI.L1-3.14.2is based onNIST SP 800-171 Requirement 3.14.2, which requires organizations to:

Implement malicious code protection(e.g., antivirus, endpoint security software).

Ensure coverage across all appropriate locations(e.g., workstations, servers, network entry points).

Keep protection mechanisms updated(e.g., regular signature updates, policy enforcement).

Assessment Criteria for a "MET" Rating:

To determine whether the practice isMET, the Lead Assessor must confirm that:

✔Antivirus or endpoint protection software is installedon all workstations and servers.

✔The solution is centrally managed, ensuring consistent policy enforcement.

✔Signature updates are current, meaning systems are protected against new threats.

✔Logs or reports demonstrate active monitoring and updates.

Why is the Correct Answer "A. It is sufficient, and the audit finding can be rated as MET"?

The provided evidenceconfirms all necessary requirementsfor SI.L1-3.14.2:

✔All workstations and servers have antivirus installed→Meets installation requirement.

✔A centralized management console is in place→Ensures consistent enforcement.

✔Records show antivirus signatures are up to date→Confirms system protection is current.

Because the evidencemeets the requirement, the practice should berated as MET.

Why Are the Other Answers Incorrect?

B. It is insufficient, and the audit finding can be rated NOT MET → Incorrect

The evidence providedmeets all necessary requirements, so the practiceshould not be rated as NOT MET.

C. It is sufficient, and the Lead Assessor should seek more evidence → Incorrect

Ifadequate evidence already exists,additional evidence is unnecessary.

D. It is insufficient, and the Lead Assessor should seek more evidence → Incorrect

The evidence providedmeets the control requirements, making itsufficient.

CMMC 2.0 References Supporting This Answer:

CMMC Assessment Process (CAP) Document

Specifies that a practice can be marked asMET if sufficient evidence is provided.

NIST SP 800-171 (Requirement 3.14.2)

Defines the standard formalicious code protection, which ismet by antivirus with active updates.

CMMC 2.0 Level 1 (Foundational) Requirements

Clarifies that basic cybersecurity measures likeantivirus installation and updatesmeet compliance forSI.L1-3.14.2.

Final Answer:

✔A. It is sufficient, and the audit finding can be rated as MET.

Step 1: Understanding CMMC Level 1 Self-Assessment Scope

CMMC Level 1applies toFederal Contract Information (FCI)systems.

Any system or device that is connected to an FCI-handling network is within the assessment scopebecause it canintroduce vulnerabilitiesinto the environment.

Step 2: Why the Thermostat is in Scope

TheWi-Fi-enabled thermostat is connected to the FCI network, meaning it haspotential accessto sensitive contract-related data.

PerCMMC Scoping Guidance, this type of device is classified as aRestricted Information System (Restricted IS)—devices that do not store, process, or transmit FCI but areconnected to networks that do.

Restricted IS must be accounted for in the self-assessment scope to ensure they do not compromise security controls.

Control Reference: CA.L2-3.12.1

CA.L2-3.12.1:"Periodically assess the security controls in organizational systems to determine if the controls are effective in their application."

This control is derived fromNIST SP 800-171, Requirement 3.12.1, which mandates organizations to performregular security control assessmentsto ensure compliance and effectiveness.

Assessment Criteria & Justification for the Correct Answer:

Evidence Review & Assessment Timeline:

The organization's procedureexplicitly statesthat security control assessments must be conductedquarterly(every three months).

Since the Lead Assessor only has access to thefirst-quarter report, the second-quarter report is missing at the time of assessment.

CMMC Audit Requirements:

For an assessor to rate a control asMET, sufficient evidence must bereadily availableat the time of evaluation.

Since the second-quarter report is missingat the time of assessment, the Lead Assessorcannot verify compliancewith the organization's own stated frequency of assessment.

Why the Answer is NOT A, C, or D:

A (Sufficient, MET)→Incorrect: The control assessment frequency is quarterly, but the evidence for Q2 is not available. Compliance cannot be confirmed.

C (Sufficient, and re-rate later)→Incorrect: If evidence is not available during the audit, the controlcannot be rated as MET initially. There is no provision in CMMC 2.0 to "conditionally" pass a control pending future evidence.

D (Insufficient, but re-rate later)→Incorrect: Once a control is ratedNOT MET, it staysNOT METuntil a re-assessment is conducted in a new audit cycle. The assessordoes not adjust ratings retroactivelybased on future evidence.

Official CMMC 2.0 References Supporting the Answer:

CMMC Assessment Process (CAP) Guide (2023):

"For a control to be rated as MET, the assessed organization must provide sufficient evidence at the time of the assessment."

"If evidence is missing or incomplete, the finding shall be rated as NOT MET."

NIST SP 800-171A (Security Requirement Assessment Guide):

"Evidence must be current, relevant, and sufficient to demonstrate compliance with stated periodicity requirements."

Since the procedure mandatesquarterly assessments, missing evidence means compliancecannot be validated.

DoD CMMC Scoping Guidance:

"Assessors shall base their determination on the evidence provided at the time of assessment. If required evidence is not available, the control shall be rated as NOT MET."

Final Conclusion:

Thecorrect answer is Bbecause the required evidence (the second-quarter report) is not availableat the time of assessment, making itinsufficientto validate compliance. The Lead Assessormust rate the control as NOT METin accordance with CMMC 2.0 assessment rules.