EvidenceSheet
NIST SP 800-53 Rev 5 · CM - Configuration Management

CM-7(1) Least Functionality | Periodic Review

(a) Review the system organization-defined frequency to identify unnecessary and/or nonsecure functions, ports, protocols, software, and services; and (b) Disable or remove organization-defined functions, ports, protocols, software, and services within the system deemed to be unnecessary and/or nonsecure.

Source: NIST SP 800-53 Rev 5, CM-7(1). The statement above is our statement of the clause, read from the published text and cited so you can check it against the official text, not the instrument verbatim. Open NIST SP 800-53 Rev 5 in the compliance library.

Base controls and their enhancements. Which apply follows the baseline you are assessed against (for example FedRAMP Moderate or High, or the low, moderate and high baselines of SP 800-53B). Text in square brackets is a parameter your organisation sets.

10
artefacts
1
held by a system
3
at each review
hard
to go live
Policy repository / GRC workspace
where the evidence lives
teal = a system already holds it · olive = produced at each review. To go live: easy when half or more of the artefacts are already held by a system, moderate from a quarter to a half, hard below a quarter.

These are the artefacts auditors commonly ask for on this requirement, our guidance rather than text from the standard. Your assessor decides what is sufficient in your context, and asks for samples across the period when a report covers one.

system holds itEvidence a system already holds

  • Change control records · Cloud console / configuration management

periodic reviewEvidence produced at each review

  • Documented reviews of functions, ports, protocols, and/or services · Cloud console / configuration management
  • System audit records · Cloud console / configuration management
  • Test of Organizational processes for reviewing or disabling functions, ports, protocols, and services on the system; mechanisms implementing review and disabling of functions, ports, protocols, and/or services · Cloud console / configuration management

governing documentDocuments that govern the control

  • Configuration management policy · Policy repository / GRC workspace
  • Procedures addressing least functionality in the system · Policy repository / GRC workspace
  • Configuration management plan · Policy repository / GRC workspace
  • System design documentation · Policy repository / GRC workspace
  • System configuration settings and associated documentation · Policy repository / GRC workspace
  • Common secure configuration checklists · Policy repository / GRC workspace

First move

Mostly documents and reviews. Pull the 1 system-held artefact from your Cloud console / configuration management on a schedule; put the documents under version control with an owner and review date, and log each review as a dated record with a named reviewer.

Common gaps auditors find

Do this for your whole sheet

Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.

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CM-7 Least Functionality · CM-7(2) Least Functionality | Prevent Program Execution