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NIST SP 800-53 Learning Center

AU-3 — Content of Audit Records

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

3Enhancements
0Parameters
3Baseline memberships
3Assessment methods

AU — Audit and Accountability · NIST SP 800-53 Release 5.2.0

LowModerateHigh
Official NIST control content

Control statement

Ensure that audit records contain information that establishes the following:

  1. a.What type of event occurred;
  2. b.When the event occurred;
  3. c.Where the event occurred;
  4. d.Source of the event;
  5. e.Outcome of the event; and
  6. f.Identity of any individuals, subjects, or objects/entities associated with the event.
Official NIST discussion

Discussion

Audit record content that may be necessary to support the auditing function includes event descriptions (item a), time stamps (item b), source and destination addresses (item c), user or process identifiers (items d and f), success or fail indications (item e), and filenames involved (items a, c, e, and f) . Event outcomes include indicators of event success or failure and event-specific results, such as the system security and privacy posture after the event occurred. Organizations consider how audit records can reveal information about individuals that may give rise to privacy risks and how best to mitigate such risks. For example, there is the potential to reveal personally identifiable information in the audit trail, especially if the trail records inputs or is based on patterns or time of usage.

Original Bare Metal Cyber perspective

From control text to operational evidence

Use Content of Audit Records as a testable risk decision. Translate the official statement into accountable people, repeatable processes, configured technology, and evidence that demonstrates the outcome over time. In this family, pay particular attention to audit event design, trustworthy collection, retention, review, and investigation support.

Implementation workflow

  • Define the control boundary, responsible owner, inherited portions, and systems or processes in scope.
  • Resolve each organization-defined parameter before declaring the control implemented.
  • Document how the implementation satisfies every clause of the official control statement.
  • Collect evidence as a normal byproduct of operation rather than only before an assessment.
  • Review exceptions, changes, and monitoring results on a risk-based cadence.

Evidence examples

  • logging standards and event-selection decisions
  • sample audit records and retention settings
  • time-synchronization evidence
  • alert and review records

Common failure patterns

  • collecting logs without defined use cases
  • critical events missing from the audit trail
  • retention shorter than investigative needs
  • logs accessible to the same administrators being monitored

Questions practitioners should ask

  • What risk decision is this control intended to support in this system?
  • Which parts are implemented locally, inherited, shared, or not applicable—and what evidence supports that decision?
  • Do the documented narrative, deployed configuration, operating process, and collected evidence agree?
  • What event or threshold requires the implementation to be reviewed or changed?
Official NIST SP 800-53A content

Assessment objectives and methods

Show the assessment objective
  1. AU-03a.audit records contain information that establishes what type of event occurred;
  2. AU-03b.audit records contain information that establishes when the event occurred;
  3. AU-03c.audit records contain information that establishes where the event occurred;
  4. AU-03d.audit records contain information that establishes the source of the event;
  5. AU-03e.audit records contain information that establishes the outcome of the event;
  6. AU-03f.audit records contain information that establishes the identity of any individuals, subjects, or objects/entities associated with the event.

Examine

  • Audit and accountability policy
  • system security plan
  • privacy plan
  • procedures addressing content of audit records
  • system design documentation
  • system configuration settings and associated documentation
  • list of organization-defined auditable events
  • system audit records
  • system incident reports
  • other relevant documents or records

Interview

  • Organizational personnel with audit and accountability responsibilities
  • organizational personnel with information security and privacy responsibilities
  • system/network administrators

Test

  • Mechanisms implementing system auditing of auditable events
Official relationships

Related controls

These relationships come from the official OSCAL catalog. They indicate useful dependencies or context, not automatic inheritance or equivalence.

MITRE D3FEND semantic mapping

Related defensive techniques

D3FEND maps this base control or one of its enhancements to the following defensive techniques. The ontology relation label is preserved and does not by itself prove implementation or effectiveness.

MITRE D3FEND™ and the D3FEND logo are trademarks of The MITRE Corporation. Bare Metal Cyber is not affiliated with or endorsed by MITRE.

Official NIST enhancements

Control enhancements

Enhancements add specificity, strength, or scope to the base control. Baseline badges show explicit selections in the official SP 800-53B OSCAL profiles.

Official NIST control enhancement

AU-3(1) — Additional Audit Information

ModerateHigh

Generate audit records containing the following additional information: [Organization-defined: additional information].

Official discussion

The ability to add information generated in audit records is dependent on system functionality to configure the audit record content. Organizations may consider additional information in audit records including, but not limited to, access control or flow control rules invoked and individual identities of group account users. Organizations may also consider limiting additional audit record information to only information that is explicitly needed for audit requirements. This facilitates the use of audit trails and audit logs by not including information in audit records that could potentially be misleading, make it more difficult to locate information of interest, or increase the risk to individuals' privacy.

Organization-defined parameters (1)
additional informationadditional information to be included in audit records is defined;
Assessment objectives and methods

generated audit records contain the following [Organization-defined: additional information].

Examine

  • Audit and accountability policy
  • procedures addressing content of audit records
  • system security plan
  • privacy plan
  • system design documentation
  • system configuration settings and associated documentation
  • list of organization-defined auditable events
  • system audit records
  • other relevant documents or records

Interview

  • Organizational personnel with audit and accountability responsibilities
  • organizational personnel with information security and privacy responsibilities
  • system/network administrators
  • system developers

Test

  • system audit capability
Official NIST control enhancement

AU-3(2) — Centralized Management of Planned Audit Record Content

Withdrawn

This enhancement is marked withdrawn in the official OSCAL catalog. Related-control metadata below may identify where its intent was incorporated.

Official NIST control enhancement

AU-3(3) — Limit Personally Identifiable Information Elements

Privacy

Limit personally identifiable information contained in audit records to the following elements identified in the privacy risk assessment: [Organization-defined: elements].

Official discussion

Limiting personally identifiable information in audit records when such information is not needed for operational purposes helps reduce the level of privacy risk created by a system.

Organization-defined parameters (1)
elementselements identified in the privacy risk assessment are defined;
Assessment objectives and methods

personally identifiable information contained in audit records is limited to [Organization-defined: elements] identified in the privacy risk assessment.

Examine

  • Audit and accountability policy
  • system security plan
  • privacy plan
  • privacy risk assessment
  • privacy risk assessment results
  • procedures addressing content of audit records
  • system design documentation
  • system configuration settings and associated documentation
  • list of organization-defined auditable events
  • system audit records
  • third party contracts
  • other relevant documents or records

Interview

  • Organizational personnel with audit and accountability responsibilities
  • organizational personnel with information security and privacy responsibilities
  • system/network administrators
  • system developers

Test

  • system audit capability
Related controls
Source record

Authoritative sources