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AU-12: AUDIT GENERATION

TAILORED FOR INDUSTRIAL CONTROL SYSTEMS

  • ICS Control Baselines:
  • Low
  • Moderate
  • High

The information system:

    • a. Provides audit record generation capability for the auditable events defined in AU-2 a. at [Assignment: organization-defined information system components];
    • b. Allows [Assignment: organization-defined personnel or roles] to select which auditable events are to be audited by specific components of the information system; and
    • c. Generates audit records for the events defined in AU-2 d. with the content defined in AU-3.

SUPPLEMENTAL GUIDANCE

Audit records can be generated from many different information system components. The list of audited events is the set of events for which audits are to be generated. These events are typically a subset of all events for which the information system is capable of generating audit records.

ICS SUPPLEMENTAL GUIDANCE

No ICS Supplemental Guidance.

CONTROL ENHANCEMENTS

AU-12 (1) AUDIT GENERATION | SYSTEM-WIDE / TIME-CORRELATED AUDIT TRAIL
  • ISC Control Baseline:
  • High

The information system compiles audit records from [Assignment: organization-defined information system components] into a system-wide (logical or physical) audit trail that is time-correlated to within [Assignment: organization-defined level of tolerance for the relationship between time stamps of individual records in the audit trail].

Supplemental Guidance:

Audit trails are time-correlated if the time stamps in the individual audit records can be reliably related to the time stamps in other audit records to achieve a time ordering of the records within organizational tolerances.

ICS Supplemental Guidance:

Example compensating controls include providing time-correlated audit records on a separate information system.

RELATED CONTROLS: AU-12 (1)

AU-12 (2) AUDIT GENERATION | STANDARDIZED FORMATS

NOT SELECTED FOR THE NIST ISC CONTROL SET

The information system produces a system-wide (logical or physical) audit trail composed of audit records in a standardized format.

Supplemental Guidance:

Audit information that is normalized to common standards promotes interoperability and exchange of such information between dissimilar devices and information systems. This facilitates production of event information that can be more readily analyzed and correlated. Standard formats for audit records include, for example, system log records and audit records compliant with Common Event Expressions (CEE). If logging mechanisms within information systems do not conform to standardized formats, systems may convert individual audit records into standardized formats when compiling system-wide audit trails.

AU-12 (3) AUDIT GENERATION | CHANGES BY AUTHORIZED INDIVIDUALS
  • ISC Control Baseline:
  • High

The information system provides the capability for [Assignment: organization-defined individuals or roles] to change the auditing to be performed on [Assignment: organization-defined information system components] based on [Assignment: organization-defined selectable event criteria] within [Assignment: organization-defined time thresholds].

Supplemental Guidance:

This control enhancement enables organizations to extend or limit auditing as necessary to meet organizational requirements. Auditing that is limited to conserve information system resources may be extended to address certain threat situations. In addition, auditing may be limited to a specific set of events to facilitate audit reduction, analysis, and reporting. Organizations can establish time thresholds in which audit actions are changed, for example, near real-time, within minutes, or within hours.

ICS Supplemental Guidance:

Example compensating controls include employing non-automated mechanisms or procedures.

RELATED CONTROLS: AU-12 (3)

REFERENCES:

  • NIST Special Publication 800-82 | GUIDE TO INDUSTRIAL CONTROL SYSTEMS (ICS) SECURITY