CMMC Navigatorby Foxx Cyber Bedrock CMMC

↑↓ to move, Enter to open, Esc to close. Try 3.5.3, AC.L2-3.1.1, MFA or unmarked.

3.1.2Limit what each person can do once inside

Being allowed in is not the same as being allowed to do everything. Define what each role may do.

The requirement, verbatim

NIST SP 800-171 Rev. 2 · 3.1.2

Limit system access to the types of transactions and functions that authorized users are permitted to execute.

Requirement 3.1.2, practice name in the CMMC assessment guide: Transaction & Function Control.

NIST's discussion

Organizations may choose to define access privileges or other attributes by account, by type of account, or a combination of both. System account types include individual, shared, group, system, anonymous, guest, emergency, developer, manufacturer, vendor, and temporary. Other attributes required for authorizing access include restrictions on time-of-day, day-of-week, and point-of-origin. In defining other account attributes, organizations consider system-related requirements (e.g., system upgrades scheduled maintenance,) and mission or business requirements, (e.g., time zone differences, customer requirements, remote access to support travel requirements).

NIST SP 800-171 Rev. 2, discussion under 3.1.2. Whitespace normalised; wording unchanged.

Assessment objectives

An assessor decides each of these separately. The requirement is met only when every objective is.

  1. [a] the types of transactions and functions that authorized users are permitted to execute are defined
  2. [b] system access is limited to the defined types of transactions and functions for authorized users

NIST SP 800-171A, determination statements for 3.1.2.

For assessors: examine, interview, test

NIST SP 800-171A names what an assessor may examine, whom they may interview, and what they may test for this requirement. Assessors select from these lists; they are not a checklist of everything you must produce.

Examine
  • Access control policy
  • procedures addressing access enforcement
  • system security plan
  • system design documentation
  • list of approved authorizations including remote access authorizations
  • system audit logs and records
  • system configuration settings and associated documentation
  • other relevant documents or records
Interview
  • Personnel with access enforcement responsibilities
  • personnel with information security responsibilities
  • system or network administrators
  • system developers
Test
  • Mechanisms implementing access control policy

NIST SP 800-171A, potential assessment methods and objects for 3.1.2.

Evidence

No evidence examples are published for this requirement yet. The objectives above are what an assessor checks; evidence is whatever shows each one is true in your environment, dated and kept with your system security plan.

Scoring weight

Worth 5 points. Not meeting this requirement subtracts 5 from your 110-point SPRS score. These are the requirements with the largest effect on your posture.

DoD NIST SP 800-171 Assessment Methodology v1.2.1 weighting, as carried in the Bedrock scoring table. The score starts at 110 and subtracts the weight of every requirement not met.

In Rev. 3

Rev. 2 is what your contract requires today. A standing DoD class deviation keeps Rev. 2 in force; NIST has published Rev. 3, but it is not adopted for contracts. In Rev. 3 this requirement is no significant change: 03.01.02 Access Enforcement.

See the Rev. 2 and Rev. 3 wording word by word, or start with the status page.

Where this page's facts come from
Requirement text
bedrock-cmmc-api@89b8e8e:migrations/004_reference_requirements.sql#Requirement.basicRequirement@rev2
Discussion
bedrock-cmmc-api@89b8e8e:migrations/004_reference_requirements.sql#Requirement.discussion@rev2
Practice name
bedrock-cmmc-api@89b8e8e:migrations/004_reference_requirements.sql#Requirement.title@rev2 (CMMC Assessment Guide practice name)
Objectives
bedrock-cmmc-api@89b8e8e:migrations/005_reference_objectives.sql#AssessmentObjective.description@rev2
Examine, interview, test
bedrock-cmmc-api@89b8e8e:migrations/005_reference_objectives.sql#AssessmentObjective.description@rev2 ({examineGuidance, interviewGuidance, testGuidance})
Level
bedrock-cmmc-api@89b8e8e:migrations/021_fix_level1_requirements.sql#Requirement.cmmcLevel@rev2
Weight
bedrock-cmmc-api@89b8e8e:internal/cmmc/requirement_values.go#requirementValues (DoD AM v1.2.1 / eMASS L2 template v3.8)
Rev. 3 mapping
bedrock-cmmc-api@89b8e8e:docs/reference/nist-800-171-rev3/normalized/r2_r3_transition_map.json#r2_to_r3
Plain-language title and summary
editorial/CMMC Navigator.dc.html#RAW (Foxx Cyber editorial)