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NIST SP 800-171 CUI Protection Center

03.12.01 — Security Assessment

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.

1Parameters
1Source controls
1Assessment objectives
3Assessment methods

03.12 — Security Assessment and Monitoring · NIST SP 800-171 Revision 3

Active
Official NIST requirement content

Security requirement

Assess the security requirements for the system and its environment of operation [Organization-defined: frequency] to determine if the requirements have been satisfied.

Official NIST discussion

Discussion

By assessing the security requirements, organizations determine whether the necessary safeguards and countermeasures are implemented correctly, operating as intended, and producing the desired outcome. Security assessments identify weaknesses in the system and provide the essential information needed to make risk-based decisions. Security assessment reports document assessment results in sufficient detail as deemed necessary by the organization to determine the accuracy and completeness of the reports. Security assessment results are provided to the individuals or roles appropriate for the types of assessments being conducted.

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.

frequencyorganization-defined frequencythe frequency at which to assess the security requirements for the system and its environment of operation is defined.
Bare Metal Cyber interpretation

Implementation perspective

Treat Security Assessment as a CUI protection outcome that must be reflected in the system boundary, documented implementation, operational behavior, and assessment evidence. Pay particular attention to assessment planning, evidence quality, remediation, continuous monitoring, and system security plan accuracy.

  1. Confirm the requirement is in scope for the CUI system components, services, users, and external connections being assessed.
  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 CUI assets, data flows, users, and services are protected by this 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

  • assessment plans and reports
  • plans of action and milestones
  • system security plans
  • continuous monitoring results

Common failure patterns

  • requirement status based only on owner assertion
  • findings closed without evidence
  • scope missing inherited services
  • monitoring data disconnected from risk decisions
Official NIST SP 800-171A content

Assessment objectives and methods

Assessment objectives (1)
  1. SR-03.12.1.

    the security requirements for the system and its environment of operation are assessed [Organization-defined: frequency] to determine if the requirements have been satisfied.

Examine

  • security assessment and monitoring policy and procedures
  • procedures for security assessment planning
  • security assessment plan
  • security assessment report
  • system security plan
  • other relevant documents or records

Interview

  • personnel with security assessment responsibilities
  • personnel with information security responsibilities

Test

  • mechanisms for supporting security assessments, processes for security assessment plan development, or security assessment reporting
Official source-control relationships

Source NIST SP 800-53 controls

These controls are referenced by the official SP 800-171 Rev. 3 OSCAL record. Open the corresponding control pages for complete control text, enhancements, D3FEND mappings, and related learning.

Source record

Authoritative sources