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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2023.0969 Advisory (icsa-23-047-10) Siemens COMOS 17 February 2023 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Siemens COMOS Publisher: ICS-CERT Operating System: Network Appliance Resolution: Patch/Upgrade CVE Names: CVE-2023-24482 Original Bulletin: https://us-cert.cisa.gov/ics/advisories/icsa-23-047-10 Comment: CVSS (Max): 10.0 CVE-2023-24482 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H) CVSS Source: ICS-CERT Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - --------------------------BEGIN INCLUDED TEXT-------------------- ICS Advisory (ICSA-23-047-10) Siemens COMOS Original release date: February 16, 2023 Legal Notice All information products included in https://us-cert.cisa.gov/ics are provided "as is" for informational purposes only. The Department of Homeland Security (DHS) does not provide any warranties of any kind regarding any information contained within. DHS does not endorse any commercial product or service, referenced in this product or otherwise. Further dissemination of this product is governed by the Traffic Light Protocol (TLP) marking in the header. For more information about TLP, see https://us-cert.cisa.gov/tlp/ . As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global). 1. EXECUTIVE SUMMARY o CVSS v3 10.0 o ATTENTION: Exploitable remotely/low attack complexity o Vendor: Siemens o Equipment: COMOS o Vulnerability: Classic Buffer Overflow 2. RISK EVALUATION Successful exploitation of this vulnerability could allow a malicious cyber actor to execute arbitrary code on the target system or cause a denial-of-service condition. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS The following Siemens software is affected: o COMOS V10.2: All versions o COMOS V10.3.3.1: Versions prior to V10.3.3.1.45 o COMOS V10.3.3.2: Versions prior to V10.3.3.2.33 o COMOS V10.3.3.3: Versions prior to V10.3.3.3.9 o COMOS V10.3.3.4: Versions prior to V10.3.3.4.6 o COMOS V10.4.0.0: Versions prior to V10.4.0.0.31 o COMOS V10.4.1.0: Versions prior to V10.4.1.0.32 o COMOS V10.4.2.0: Versions prior to V10.4.2.0.25 3.2 VULNERABILITY OVERVIEW 3.2.1 BUFFER COPY WITHOUT CHECKING SIZE OF INPUT ('CLASSIC BUFFER OVERFLOW') CWE-120 Cache validation service in COMOS is vulnerable to structured exception handler (SEH)-based buffer overflow. This could allow a malicious cyber actor to execute arbitrary code on the target system or cause a denial-of-service condition. CVE-2023-24482 has been assigned to this vulnerability. A CVSS v3 base score of 10.0 has been calculated. The CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/ UI:N/S:C/C:H/I:H/A:H ). 3.3 BACKGROUND o CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing o COUNTRIES/AREAS DEPLOYED: Worldwide o COMPANY HEADQUARTERS LOCATION: Germany 3.4 RESEARCHER Siemens reported this vulnerability to CISA. 4. MITIGATIONS Siemens has released updates for the affected products and recommends users update to the latest versions: o COMOS V10.4.2.0: Update to V10.4.2.0.25 or later version o COMOS V10.4.1.0: Update to V10.4.1.0.32 or later version o COMOS V10.4.0.0: Update to V10.4.0.0.31 or later version o COMOS V10.3.3.4: Update to V10.3.3.4.6 or later version o COMOS V10.3.3.3: Update to V10.3.3.3.9 or later version o COMOS V10.3.3.2: Update to V10.3.3.2.33 or later version o COMOS V10.3.3.1: Update to V10.3.3.1.45 or later version o COMOS V10.2: Currently no fix is planned Siemens has identified the following workarounds and mitigations users can apply to mitigate risk: o Enable structured exception handling overwrite protection (SEHOP) in the Windows operating system where COMOS is installed to protect against code execution. However, the application would remain vulnerable to denial-of-service condition attacks As a general security measure, Siemens strongly recommends protecting network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for Industrial Security , and to follow the recommendations in the product manuals. Additional information on industrial security by Siemens can be found on the Siemens Industrial Security webpage . For further inquiries on security vulnerabilities in Siemens products and solutions, users should contact the Siemens ProductCERT . For more information, see the associated Siemens security advisory SSA-693110 in HTML and CSAF . CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should: o Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the Internet . o Locate control system networks and remote devices behind firewalls and isolate them from business networks. o When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as its connected devices. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. CISA also provides a section for control systems security recommended practices on the ICS webpage at cisa.gov/ics . Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies . Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies . Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. For any questions related to this report, please contact the CISA at: Email: CISAservicedesk@cisa.dhs.gov Toll Free: 1-888-282-0870 CISA continuously strives to improve its products and services. You can help by choosing one of the links below to provide feedback about this product. - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://www.auscert.org.au/bulletins/ =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: https://auscert.org.au/gpg-key/ iQIVAwUBY+7YjskNZI30y1K9AQgyKg/+Lm0xlZW/n5tDvrJws8wK34yPeVqpDHn/ E+bJou+Sm5KWkdPdRgB593qiBZjBNF4xBL96V7j+fN0qIsZZMqDWq0wUX9LjU5lf Lq1yN3NXGd0XL40qgo27P5GxK190NnlDQH26n5QRGNZMQtVCsipu582xpWCHBXmJ 3JokvXf857KW/vGtcVCABkSkFBeQbdg9RV/C4zvI/WsCRDxmRPgSDPDidYP7pvXZ xVdw7nUkPHjZTerIJRVmZB5atC2wkfDFAKLXn52DUtYH3GExwG/kWAj53P8jAv9H 3TnVAi9YQYo1lPzbLD/hsz0p7sImZVtYPm+kTMNznq8AmMFDKuiH+w8uGYNtr/OK UBZj38x0yO2/GMUt014XKtaXEaJX2UCK3VuLnUJk2E9YvaebKhwzFQDSL0HyjojU +cq/vkMFZ6O/4/qZeGizbfBBvmTCYbVOLxyBSM0OnqIDXj8ZXdldVCFDP+ch++yq g10Pa+CTaSj7Xgy55icvi09SBrtpQgurmkD+l/pYz/kwBsNlY0GKAQJiYHniJD2r zNBGNcBZWxMGi6UTrWLpVdFrzMr3lD30VClmwt87ryo2TVMWENTV9QogLBlGUpVg vip1mVqvGyIKVfnc7TcUc9FXGxH0z48+f/84LppPdjfXb9sqpLtv5jujIlBvIAvt urHq8ywlIu8= =NP0W -----END PGP SIGNATURE-----