DISCUSSION [NIST SP 800-171 R2]
Organizations identify systems that are affected by announced software and firmware flaws including potential vulnerabilities resulting from those flaws and report this information to designated personnel with information security responsibilities. Security-relevant updates include patches, service packs, hot fixes, and anti-virus signatures. Organizations address flaws discovered during security assessments, continuous monitoring, incident response activities, and system error handling. Organizations can take advantage of available resources such as the Common Weakness Enumeration (CWE) database or Common Vulnerabilities and Exposures (CVE) database in remediating flaws discovered in organizational systems.
Organization-defined time periods for updating security-relevant software and firmware may vary based on a variety of factors including 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 of remediation. NIST SP 800-40 provides guidance on patch management technologies.
FURTHER DISCUSSION
All software and firmware have potential flaws. Many vendors work to remedy those flaws by releasing vulnerability information and updates to their software and firmware. Contractors must have a process to review relevant vendor notifications and updates about problems or weaknesses. After reviewing the information, the contractor must implement a patch management process that allows for software and firmware flaws to be fixed without adversely affecting the system functionality. Contractors must define the time frames within which flaws are identified, reported, and corrected for all systems. Contractors should consider purchasing support from their vendors to ensure timely access to updates.
Example
You know that software vendors typically release patches, service packs, hot fixes, etc. and want to make sure your software is up to date. You develop a policy that requires checking vendor websites for flaw notifications every week [a]. The policy further requires that those flaws be assessed for severity and patched on end-user computers once each week and servers once each month [c,e]. Consistent with that policy, you configure the system to check for updates weekly or daily depending on the criticality of the software [b,e]. Your team
reviews available updates and implements the applicable ones according to the defined schedule [f].
Potential Considerations
Is the time frame (e.g., a set number of days) within which system flaw identification activities (e.g., vulnerability scans, configuration scans, manual review) must be performed defined and documented [a]?
Are system flaws (e.g., vulnerabilities, misconfigurations) identified in accordance with the specified time frame [b]?
Is the time frame (e.g., a set number of days dependent on the assessed severity of a flaw) within which system flaws must be corrected defined and documented [e]?
Are system flaws (e.g., applied security patches, made configuration changes, or implemented workarounds or mitigations) corrected in accordance with the specified time frame [f]?
Copyright
Copyright 2020, 2021 Carnegie Mellon University and The Johns Hopkins University Applied Physics Laboratory LLC.
Copyright 2021 Futures, Inc.
This material is based upon work funded and supported by the Department of Defense under Contract No. FA8702-15-D-0002 with Carnegie Mellon University for the operation of the Software Engineering Institute, a federally funded research and development center, and under Contract No. HQ0034-13-D-0003 and Contract No. N00024-13-D-6400 with the Johns Hopkins University Applied Physics Laboratory LLC, a University Affiliated Research Center.
The view, opinions, and/or findings contained in this material are those of the author(s) and should not be construed as an official Government position, policy, or decision, unless designated by other documentation.
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