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NIST SP 800-172 Enhanced CUI Protection Center

03.01.08E — Account Monitoring for Atypical Usage

Read the official CUI requirement and assessment content, then use the separately labeled Bare Metal Cyber perspective to connect it to implementation, evidence, and sustained operation.

2Parameters
1Source controls
2Assessment objectives
3Assessment methods

03.01 — Access Control · NIST SP 800-172 Revision 3

Active
Official NIST requirement content

Security requirement

  1. a.Monitor system accounts for [Organization-defined: atypical usage].
  2. b.Report atypical usage of system accounts to [Organization-defined: personnel or roles].
Official NIST discussion

Discussion

Atypical usage includes accessing systems at certain times of the day or from locations that are not consistent with the normal usage patterns of individuals. Monitoring for atypical usage may reveal rogue behavior by individuals or an attack in progress. This requirement enhances SP 800-171 requirement 03.01.01.

Official organization-defined parameters

Tailoring decisions required

Resolve these values through the governing organization’s approved tailoring and risk-management process before declaring the requirement implemented.

atypical usageorganization-defined atypical usageatypical usage for which to monitor system accounts is defined.
personnel or rolesorganization-defined personnel or rolespersonnel or roles to report atypical usage are defined.
Official protection strategy classifications

Protection strategies supported

These classifications are carried from the official SP 800-172 OSCAL record and help explain the enhanced requirement’s defensive purpose.

PS-DLODamage-Limiting Operations
Bare Metal Cyber interpretation

Implementation perspective

Treat Account Monitoring for Atypical Usage as an enhanced CUI protection outcome for elevated threat conditions that must be reflected in the system boundary, documented implementation, operational behavior, and assessment evidence. Pay particular attention to approved identities, least privilege, remote access, information flow, and the full account lifecycle.

  1. Confirm the federal agency selected this enhanced requirement for the critical program or high-value asset and identify the CUI system components, services, users, and external connections in scope.
  2. Resolve every organization-defined parameter through an approved governance and tailoring process.
  3. Map each clause of the requirement to an accountable owner, implementation mechanism, and evidence source.
  4. Verify that inherited and shared implementations are supported by current provider evidence and responsibility boundaries.
  5. Collect evidence during normal operation and review changes, exceptions, and deficiencies on a risk-based cadence.

Questions to ask

  • Which critical-program or high-value-asset CUI, data flows, users, and services are protected by this enhanced requirement?
  • Which portions are implemented locally, inherited, shared, or not applicable, and what evidence supports that determination?
  • Do the system security plan, deployed configuration, operating process, and assessment evidence tell the same story?
  • What change, incident, or threshold should trigger reassessment?

Evidence and validation

  • access authorization and approval records
  • account inventories and entitlement exports
  • access review results
  • authentication and authorization logs

Common failure patterns

  • CUI access that exceeds mission need
  • shared or orphaned accounts
  • remote access paths outside the approved boundary
  • access reviews that cannot be reconciled to deployed permissions
Official NIST SP 800-172A content

Assessment objectives and methods

Assessment objectives (2)
  1. a.

    system accounts are monitored for [Organization-defined: atypical usage].

  2. b.

    atypical usage of system accounts is reported to [Organization-defined: personnel or roles].

Examine

  • Access control policy
  • procedures addressing account management
  • system design documentation
  • system configuration settings and associated documentation
  • system monitoring records
  • system audit records
  • audit tracking and monitoring reports
  • system security plan
  • other relevant documents or records

Interview

  • Personnel with account management responsibilities
  • system/network administrators
  • personnel with information security responsibilities

Test

  • Mechanisms implementing account management functions
Official source-control relationships

Source NIST SP 800-53 controls

These controls are referenced by the official SP 800-172 Rev. 3 OSCAL record. Open the corresponding control pages for complete control text, enhancements, D3FEND mappings, and related learning.

Source controlAC-2(12)Open SP 800-53 control →
Source record

Authoritative sources

Bare Metal Cyber is an independent educational publisher and is not affiliated with or endorsed by NIST. The official publications, the responsible federal agency, and the governing contract or agreement determine applicability, tailoring, assessment depth, and required implementation.