3.1.4Split duties so one person cannot do everything alone

Separate the roles that could hide a mistake or a theft if one person held them all.

The requirement, verbatim

NIST SP 800-171 Rev. 2 · 3.1.4
Separate the duties of individuals to reduce the risk of malevolent activity without collusion.

Requirement 3.1.4, practice name in the CMMC assessment guide: Separation of Duties.

NIST's discussion

Separation of duties addresses the potential for abuse of authorized privileges and helps to reduce the risk of malevolent activity without collusion. Separation of duties includes dividing mission functions and system support functions among different individuals or roles; conducting system support functions with different individuals (e.g., configuration management, quality assurance and testing, system management, programming, and network security); and ensuring that security personnel administering access control functions do not also administer audit functions. Because separation of duty violations can span systems and application domains, organizations consider the entirety of organizational systems and system components when developing policy on separation of duties.

NIST SP 800-171 Rev. 2, discussion under 3.1.4. Whitespace normalised; wording unchanged.

Assessment objectives

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

[a] the duties of individuals requiring separation are defined
[b] responsibilities for duties that require separation are assigned to separate individuals
[c] access privileges that enable individuals to exercise the duties that require separation are granted to separate individuals

NIST SP 800-171A, determination statements for 3.1.4.

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 divisions of responsibility and separation of duties
system security plan
system design documentation
system configuration settings and associated documentation
list of divisions of responsibility and separation of duties
system access authorizations
system audit logs and records
other relevant documents or records

Interview

Personnel with responsibilities for defining appropriate divisions of responsibility and separation of duties
personnel with information security responsibilities
system or network administrators

Test

Mechanisms implementing separation of duties policy

NIST SP 800-171A, potential assessment methods and objects for 3.1.4.

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 no significant change: 03.01.04 Separation of Duties.

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)