Control: The organisation:
Flaw Remediation Supplemental Guidance:
Organisations identify information systems affected by announced software flaws including potential vulnerabilities resulting from those flaws, and report this information to designated organisational personnel with information security responsibilities. Security-relevant software updates include, for example, patches, service packs, hot fixes, and anti-virus signatures. Organisations also address flaws discovered during security assessments, continuous monitoring, incident response activities, and system error handling. Organisations take advantage of available resources such as the Common Weakness Enumeration (CWE) or Common Vulnerabilities and Exposures (CVE) databases in remediating flaws discovered in organisational information systems. By incorporating flaw remediation into ongoing configuration management processes, required/anticipated remediation actions can be tracked and verified. Flaw remediation actions that can be tracked and verified include, for example, determining whether organisations follow US-CERT guidance and Information Assurance Vulnerability Alerts. Organisation-defined time periods for updating security-relevant software and firmware may vary based on a variety of factors including, for example, the security category of the information system or the criticality of the update (i.e., severity of the vulnerability related to the discovered flaw). Some types of flaw remediation may require more testing than other types. Organisations determine the degree and type of testing needed for the specific type of flaw remediation activity under consideration and also the types of changes that are to be configuration-managed. In some situations, organisations may determine that the testing of software and/or firmware updates is not necessary or practical, for example, when implementing simple anti-virus signature updates. Organisations may also consider in testing decisions, whether security-relevant software or firmware updates are obtained from authorised sources with appropriate digital signatures.
Related controls: CA-2, CA-7, CM-3, CM-5, CM-8, MA-2, IR-4, RA-5, SA-10, SA-11, SI-11.
Flaw Remediation Control Enhancements:
SI-2 (1) Flaw Remediation - Central Management
The organisation centrally manages the flaw remediation process.
Supplemental Guidance: Central management is the organisation-wide management and implementation of flaw remediation processes. Central management includes planning, implementing, assessing, authorising, and monitoring the organisation-defined, centrally managed flaw remediation security controls.
SI-2 (2) Flaw Remediation - Automated flaw remediation status
The organisation employs automated mechanisms [Assignment: organisation-defined frequency] to determine the state of information system components with regard to flaw remediation.
Supplemental Guidance: Related controls: CM-6, SI-4.
SI-2 (3) Flaw Remediation - Time to remediate flaws / Benchmarks for corrective actions
The organisation:
- (a) Measures the time between flaw identification and flaw remediation; and
- (b) Establishes [Assignment: organisation-defined benchmarks] for taking corrective actions.
Supplemental Guidance: This control enhancement requires organisations to determine the current time it takes on the average to correct information system flaws after such flaws have been identified, and subsequently establish organisational benchmarks (i.e., time frames) for taking corrective actions. Benchmarks can be established by type of flaw and/or severity of the potential vulnerability if the flaw can be exploited.
SI-2 (4) Flaw Remediation - Automated patch management tools
[Withdrawn: Incorporated into SI-2].
SI-2 (5) Flaw Remediation - Automatic software / firmware updates
The organisation installs [Assignment: organisation-defined security-relevant software and firmware updates] automatically to [Assignment: organisation-defined information system components].
Supplemental Guidance: Due to information system integrity and availability concerns, organisations give careful consideration to the methodology used to carry out automatic updates. Organisations must balance the need to ensure that the updates are installed as soon as possible with the need to maintain configuration management and with any mission or operational impacts that automatic updates might impose.
SI-2 (6) Flaw Remediation - Removal of previous versions of software / firmware
The organisation removes [Assignment: organisation-defined software and firmware components] after updated versions have been installed.
Supplemental Guidance: Previous versions of software and / or firmware components that are not removed from the information system after updates have been installed may be exploited by adversaries. Some information technology products may remove older versions of software and/or firmware automatically from the information system.