3.5.6Disable dormant accounts

Accounts unused for a defined period are switched off.

The requirement, verbatim

NIST SP 800-171 Rev. 2 · 3.5.6
Disable identifiers after a defined period of inactivity.

Requirement 3.5.6, practice name in the CMMC assessment guide: Identifier Handling.

NIST's discussion

Inactive identifiers pose a risk to organizational information because attackers may exploit an inactive identifier to gain undetected access to organizational devices. The owners of the inactive accounts may not notice if unauthorized access to the account has been obtained.

NIST SP 800-171 Rev. 2, discussion under 3.5.6. Whitespace normalised; wording unchanged.

Assessment objectives

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

[a] a time period of inactivity after which identifiers are disabled is defined
[b] identifiers are disabled after the defined period of inactivity

NIST SP 800-171A, determination statements for 3.5.6.

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

Identification and authentication policy
procedures addressing identifier management
procedures addressing account management
system security plan
system design documentation
system configuration settings and associated documentation
list of system accounts
list of identifiers generated from physical access control devices
other relevant documents or records

Interview

Personnel with identifier management responsibilities
personnel with information security responsibilities
system or network administrators
system developers

Test

Mechanisms supporting or implementing identifier management

NIST SP 800-171A, potential assessment methods and objects for 3.5.6.

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 1 point. Not meeting this requirement subtracts 1 from your 110-point SPRS score.

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 withdrawn with no successor.

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)