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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2019.3778.2 Advisory (icsa-19-281-03) Siemens SIMATIC WinAC RTX (F) 2010 16 January 2020 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Siemens SIMATIC WinAC RTX (F) 2010 Publisher: ICS-CERT Operating System: Windows Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2019-13921 Original Bulletin: https://www.us-cert.gov/ics/advisories/icsa-19-281-03 Revision History: January 16 2020: Source updated to clarify fix is in version SP3 Update 1 & provide more info October 9 2019: Initial Release - --------------------------BEGIN INCLUDED TEXT-------------------- ICS Advisory (ICSA-19-281-03) Siemens SIMATIC WinAC RTX (F) 2010 (Update A) Original release date: January 14, 2020 Legal Notice All information products included in http://ics-cert.us-cert.gov 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 http://www.us-cert.gov/tlp/ . 1. EXECUTIVE SUMMARY o CVSS v3 7.5 o ATTENTION: Exploitable remotely/low skill level to exploit o Vendor: Siemens o Equipment: SIMATIC WinAC RTX (F) 2010 - --------- Begin Update A Part 1 of 4 --------- o Vulnerability: Insufficient Resource Pool - --------- End Update A Part 1 of 4 --------- 2. UPDATE INFORMATION This updated advisory is a follow-up to the original advisory titled ICSA-19-281-03 Siemens SIMATIC WinAC RTX (F) 2010 that was published October 8, 2019, on the ICS webpage on us-cert.gov. 3. RISK EVALUATION Successful exploitation of this vulnerability could allow an attacker to perform a denial-of-service attack that could compromise the availability of the service provided by the software. 4. TECHNICAL DETAILS 4.1 AFFECTED PRODUCTS The following versions of Siemens SIMATIC WinAC RTX (F) 2010, software controller for PC-based automation solutions, are affected: - --------- Begin Update A Part 2 of 4 --------- o SIMATIC WinAC RTX (F) 2010 all versions prior to SP3 Update 1 - --------- End Update A Part 2 of 4 --------- 4.2 VULNERABILITY OVERVIEW - --------- Begin Update A Part 3 of 4 --------- 4.2.1 INSUFFICIENT RESOURCE POOL CWE-410 An unauthenticated attacker sending a large HTTP request to the host where WinAC RTX is running may trigger a denial-of-service condition. CVE-2019-13921 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:N/UI:N/S:U/ C:N/I:N/A:H ). - --------- End Update A Part 3 of 4 --------- 4.3 BACKGROUND o CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing o COUNTRIES/AREAS DEPLOYED: Worldwide o COMPANY HEADQUARTERS LOCATION: Germany 4.4 RESEARCHER Tal Keren from Claroty reported this vulnerability to Siemens. 5. MITIGATIONS - --------- Begin Update A Part 4 of 4 --------- Siemens recommends installing the following software update to address this vulnerability: o Update to SIMATIC WinAC RTX (F) 2010: SP3 Update 1 - --------- End Update A Part 4of 4 --------- Siemens has identified the following specific workarounds and mitigations users can apply to reduce the risk: o Restrict network access to the host containing the affected service. o If the service is not used as a server, configure Windows Firewall to disable communications on the port of the vulnerable service. 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 following the recommendations in the product manuals. Additional information on Industrial Security by Siemens can be found at: https://www.siemens.com/industrialsecurity For more information on this vulnerability and more detailed mitigation instructions, please see Siemens security advisory SSA-878278 at the following location: http://www.siemens.com/cert/advisories 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 that they are not accessible from the Internet . o Locate control system networks and remote devices behind firewalls, and isolate them from the business network. o When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that VPN is only as secure as the 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 on us-cert.gov . Several recommended 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 on us-cert.gov in the Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies . Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to CISA for tracking and correlation against other incidents. No known public exploits specifically target this vulnerability. - --------------------------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: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBXh+t+WaOgq3Tt24GAQhxHQ//WeP8aoGHGHH/bdyPOjdMSXWYM/Hka3Th PH8w4cfuHFIhJPE+lo9LNoYzD/1a4oBh3aVZ6S+Jq2DqwjFti22NwQzCIEQSXTtP 6zivs7qKc5Ia/ISS9/CLpWTu87OEKmS5V6atPMrogKVGxKc3qUVX3VO+mBRil2I4 yyvmz2wB8ff5nEmgb5PByrpOVCb2LPqgNC5Ug5c2p7opwsc7zLWE/WeVASGLLtec D8fCSIWmtqg2VUA1fod2vxgUkzjuMKRSm2OPCSHkkVXFq5itWI24NopkfC41WV99 jYIROsfTdjiEHo/LkI/2XE3A3knMh5csaE6Wd9YNBCpNjfjZXuhEIWO6Mibmagxt e0MRtT0RmAEv0HmsN+GRjVyXGLNs6A5hsJLAC4HAbS8Dm7XgVtBiVC8HPoI8oSzP BiXfJpCNTm+xaYi6uvWNLJT31ZLCnxB6QOny4Dgpz+X202czzrZ21t4sn7GtUqJd BH/jjP1i+uChPXaRiAOxu7yBDc1m51lLy+wdl69GVmtU7jJFgWg3DSAV9TOpPyiw kYhlqtst+/CXeaV8ZYyBhOhwCt7RBZWkhZR3snV02T1Qanl1T8FO2Q13/8/s6vVa DGFA0yI8pSIrw2Nb63pKoBNqQAVgNmtMSs2pMJvxxNuAbh3mAZqbvW/yorQfmJVl ATVxt3ZjF0w= =Dolu -----END PGP SIGNATURE-----