SI — SYSTEM AND INFORMATION INTEGRITY
SI-2: FLAW REMEDIATION
NIST 800-53R4 Membership SI-2:
- a. Identifies, reports, and corrects information system flaws;
- b. Tests software and firmware updates related to flaw remediation for effectiveness and potential side effects before installation;
- c. Installs security-relevant software and firmware updates within [Assignment: organization-defined time period] of the release of the updates; and
- d. Incorporates flaw remediation into the organizational configuration management process.
Organizations identify information systems affected by announced software flaws including potential vulnerabilities resulting from those flaws, and report this information to designated organizational personnel with information security responsibilities. Security-relevant software updates include, for example, patches, service packs, hot fixes, and anti-virus signatures. Organizations also address flaws discovered during security assessments, continuous monitoring, incident response activities, and system error handling. Organizations take advantage of available resources such as the Common Weakness Enumeration (CWE) or Common Vulnerabilities and Exposures (CVE) databases in remediating flaws discovered in organizational 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 organizations follow US-CERT guidance and Information Assurance Vulnerability Alerts. Organization-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. Organizations 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, organizations 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. Organizations may also consider in testing decisions, whether security-relevant software or firmware updates are obtained from authorized sources with appropriate digital signatures.
RELATED CONTROLS: SI-2
SI-2 (1) FLAW REMEDIATION | CENTRAL MANAGEMENT
NIST 800-53R4 Membership SI-2 (1):
The organization centrally manages the flaw remediation process.
Central management is the organization-wide management and implementation of flaw remediation processes. Central management includes planning, implementing, assessing, authorizing, and monitoring the organization-defined, centrally managed flaw remediation security controls.
SI-2 (2) FLAW REMEDIATION | AUTOMATED FLAW REMEDIATION STATUS
NIST 800-53R4 Membership SI-2 (2):
The organization employs automated mechanisms [Assignment: organization-defined frequency] to determine the state of information system components with regard to flaw remediation.
Supplemental Guidance: NONE
RELATED CONTROLS: SI-2 (2)
SI-2 (3) FLAW REMEDIATION | TIME TO REMEDIATE FLAWS / BENCHMARKS FOR CORRECTIVE ACTIONS
- (a) Measures the time between flaw identification and flaw remediation; and
- (b) Establishes [Assignment: organization-defined benchmarks] for taking corrective actions.
This control enhancement requires organizations to determine the current time it takes on the average to correct information system flaws after such flaws have been identified, and subsequently establish organizational 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]. (See above.)
SI-2 (5) FLAW REMEDIATION | AUTOMATIC SOFTWARE/FIRMWARE UPDATES
The organization installs [Assignment: organization-defined security-relevant software and firmware updates] automatically to [Assignment: organization-defined information system components].
Due to information system integrity and availability concerns, organizations give careful consideration to the methodology used to carry out automatic updates. Organizations 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 organization removes [Assignment: organization-defined software and firmware components] after updated versions have been installed.
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.
- NIST Special Publication 800-128
- NIST Special Publication 800-40