LLMPrompt CM.L2-3.4.6

I am a cybersecurity manager working for an organization that is a DoD contractor. I need to implement various security practices that conform to DoD's CMMC program at level 2. The CMMC program stipulates security practices that are based on NIST Special Publication 800-171 R2. For each security practice of CMMC Level 2, I need to show evidence that my organization is in compliance with CMMC. Each security practice has a security requirement and several assessment objectives that support that high-level security requirement.

I am assessing one of the assessment objectives within the practice CM.L2-3.4.6 – LEAST FUNCTIONALITY. The CMMC program has published the following assessment guidance, so take them into account as you formulate your response. Also refer to the attached CMMC Level 2 Assessment Guide, AssessmentGuideL2v2.pdf, for more context and information about the practice.

A. SECURITY REQUIREMENT: Employ the principle of least functionality by configuring organizational systems to provide only essential capabilities.

B. ASSESSMENT OBJECTIVES: Determine if: [a] essential system capabilities are defined based on the principle of least functionality; and [b] the system is configured to provide only the defined essential capabilities.

C. ASSESSMENT APPROACHES: I have three assessment approaches for assessing any security practice. They are listed as follows:

C1. Examine: The process of checking, inspecting, reviewing, observing, studying, or analyzing one or more assessment objectives to facilitate understanding, achieve clarification, or obtain evidence. The results are used to support the determination of security safeguard existence, functionality, correctness, completeness, and potential for improvement over time.

C2. Interview: The process of conducting discussion with individuals or groups of individuals in an organization to facilitate understanding, achieve clarification, or lead to the location of evidence. The results are used to support the determination of security safeguard existence, functionality, correctness, completeness, and potential for improvement over time.

C3. Test: The process of exercising one or more assessment objects under specified conditions to compare actual with expected behavior. The results are used to support the determination of security safeguard existence, functionality, correctness, completeness, and potential for improvement over time.

D. ASSESSMENT OBJECTS: Each assessment approach can yield potential assessment objects:

D1. Examine: [SELECT FROM: Configuration management policy; configuration management plan; procedures addressing least functionality in the system; system security plan; system design documentation; system configuration settings and associated documentation; security configuration checklists; other relevant documents or records].

D2. Interview: [SELECT FROM: Personnel with security configuration management responsibilities; personnel with information security responsibilities; system or network administrators].

D3. Test: [SELECT FROM: Organizational processes prohibiting or restricting functions, ports, protocols, or services; mechanisms implementing restrictions or prohibition of functions, ports, protocols, or services].

E. DISCUSSION: Systems can provide a wide variety of functions and services. Some of the functions and services routinely provided by default, may not be necessary to support essential organizational missions, functions, or operations. It is sometimes convenient to provide multiple services from single system components. However, doing so increases risk over limiting the services provided by any one component. Where feasible, organizations limit component functionality to a single function per component. Organizations review functions and services provided by systems or components of systems, to determine which functions and services are candidates for elimination. Organizations disable unused or unnecessary physical and logical ports and protocols to prevent unauthorized connection of devices, transfer of information, and tunneling. Organizations can utilize network scanning tools, intrusion detection and prevention systems, and end-point protections such as firewalls and host-based intrusion detection systems to identify and prevent the use of prohibited functions, ports, protocols, and services.

F. FURTHER DISCUSSION: You should customize organizational systems to remove non-essential applications and disable unnecessary services. Systems come with many unnecessary applications and settings enabled by default including unused ports and protocols. Leave only the fewest capabilities necessary for the systems to operate effectively.

G. Example: You have ordered a new server, which has arrived with a number of free utilities installed in addition to the operating system. Before you deploy the server, you research the utilities to determine which ones can be eliminated without impacting functionality. You remove the unneeded software, then move on to disable unused ports and services. The server that enters production therefore has only the essential capabilities enabled for the system to function in its role [a,b].

H. Potential Assessment Considerations: Are the roles and functions for each system identified along with the software and services required to perform those functions [a]? Are the software and services required for those defined functions identified [a]? Is the information system configured to exclude any function not needed in the operational environment [b]?

I. EVIDENCE TYPES: Finally, I have four evidence types that I can collect. The definitions of the evidence types are as follows:

I1. Artifacts: Tangible and reviewable records that are the direct outcome of a practice or process being performed by a system, person, or persons performing a role in that practice, control, or process. (See CAP Glossary for additional details.)

I2. Document: Any tangible thing which constitutes or contains information and means the original and any copies (whether different from the originals because of notes made on such copies or otherwise) of all writing of every kind and description over which an agency has authority. (See CAP Glossary for additional details.)

I3. Physical Review: An on-premise observation of Evidence.

I4. Screen Share: Live observation ""over the shoulder"" of a user as they share their computer screen while performing a task.

J. KEY REFERENCES: NIST SP 800-171 Rev 2 3.4.6