NIST SP 800-171 Rev 2 · 3.1 Access Control

3.1.22 CUI on public systems

Control CUI posted or processed on publicly accessible systems.

SPRS weight: 1; 1 point deducted from 110 when not implemented.
CMMC level: L1 + L2; Level 1 practice AC.L1-3.1.22, from FAR 52.204-21(b)(1)(iv)
Assessment objectives: 5; From NIST SP 800-171A, each one a “determine if” an assessor answers.

What an assessor checks

NIST SP 800-171A breaks 3.1.22 into 5 objectives. Every one has to be met for the requirement to be met; a partial answer scores as not implemented.

[a]Determine if individuals authorized to post or process information on publicly accessible systems are identified.
[b]Determine if procedures to ensure CUI is not posted or processed on publicly accessible systems are identified.
[c]Determine if a review process in in place prior to posting of any content to publicly accessible systems.
[d]Determine if content on publicly accessible information systems is reviewed to ensure that it does not include CUI.
[e]Determine if mechanisms are in place to remove and address improper posting of CUI.

Examine: [SELECT FROM: Access control policy; procedures addressing publicly accessible content; security plan; list of users authorized to post publicly accessible content on organizational systems; training materials and/or records; records of publicly accessible information reviews; records of response to nonpublic information on public websites; system audit logs and records; security awareness training records; other relevant documents or records].
Interview: [SELECT FROM: Personnel with responsibilities for managing publicly accessible information posted on organizational systems; personnel with information security responsibilities].
Test: [SELECT FROM: Mechanisms implementing management of publicly accessible content].

Not POA&M-eligible: named exclusion · 1 point deducted

Named in 32 CFR 170.21(a)(2)(iii) as barred from a Level 2 POA&M, even though it is worth a single point. It must be closed before the assessment.

A POA&M is only permitted at a score of 88 or above, and closes in one 180-day window. Check a full gap list or compute your score.

No direct mapping.

This page and the MacTech CMMC MCP server render the same dataset. Ask your assistant and it will answer from the methodology, not from memory.

lookup_control 3.1.22
get_assessment_objectives 3.1.22
generate_poam_entries ["3.1.22"]

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