This is the first edition of CAN/CSA-IEC/TR 62443-2-3, Security for industrial automation and control systems — Part 2-3: Patch management in the IACS environment, which is an adoption without modification of the identically titled IEC (International Electrotechnical Commission) Technical Report 62443-2-3 (first edition, 2015-06). At the time of publication, IEC TR 62443-2-3:2015 is available from IEC in English only. CSA Group will publish the French version when it becomes available from IEC. The IEC Technical Report is one in a series of Standards developed by IEC/TC 65 on industrial automation networking security that are being adopted by CSA Group. The IEC Technical Report addresses the patch management aspects of cyber security. It recommends a defined format for the distribution of information about security patches from asset owners to IACS product suppliers. The exchange format and activities are defined for use in security-related patches, but may also be used for non-security related patches or updates. This Standard uses terminology and concepts specified in the following: a) CAN/CSA-IEC/TS 62443-1-1:17, Industrial communication networks — Network and system security — Part 1-1: Terminology, concepts and models; and b) CAN/CSA-IEC 62443-2-1:17, Industrial communication networks — Network and system security — Part 2-1: Establishing an industrial automation and control system security program. Scope This part of IEC 62443, which is a Technical Report, describes requirements for asset owners and industrial automation and control system (IACS) product suppliers that have established and are now maintaining an IACS patch management program. This Technical Report recommends a defined format for the distribution of information about security patches from asset owners to IACS product suppliers, a definition of some of the activities associated with the development of the patch information by IACS product suppliers and deployment and installation of the patches by asset owners. The exchange format and activities are defined for use in security related patches; however, it may also be applicable for non-security related patches or updates. The Technical Report does not differentiate between patches made available for the operating systems (OSs), applications or devices. It does not differentiate between the product suppliers that supply the infrastructure components or the IACS applications; it provides guidance for all patches applicable to the IACS. Additionally, the type of patch can be for the resolution of bugs, reliability issues, operability issues or security vulnerabilities. NOTE 1 This Technical Report does not provide guidance on the ethics and approaches for the discovery and disclosure of security vulnerabilities affecting IACS. This is a general issue outside the scope of this report. NOTE 2 This Technical Report does not provide guidance on the mitigation of vulnerabilities in the period between when the vulnerability is discovered and the date that the patch resolving the vulnerability is created. For guidance on multiple countermeasures to mitigate security risks as part of an IACS security management system (IACS-SMS), refer to, Annexes B.4.5, B.4.6 and B.8.5 in this Technical Report and other documents in the IEC 62443 series.