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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2020.4045 Advisory (icsa-20-315-04) SIMATIC S7-300 CPUs and SINUMERIK Controller 13 November 2020 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: SIMATIC S7-300 CPUs SINUMERIK Controller Publisher: ICS-CERT Operating System: Network Appliance Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2020-15783 Original Bulletin: https://us-cert.cisa.gov/ics/advisories/icsa-20-315-04 - --------------------------BEGIN INCLUDED TEXT-------------------- ICS Advisory (ICSA-20-315-04) SIMATIC S7-300 CPUs and SINUMERIK Controller Original release date: November 10, 2020 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/ . 1. EXECUTIVE SUMMARY o CVSS v3 5.9 o ATTENTION: Exploitable remotely o Vendor: Siemens o Equipment: SIMATIC S7-300 CPUs and SINUMERIK Controller o Vulnerability: Uncontrolled Resource Consumption 2. RISK EVALUATION Successful exploitation of this vulnerability could allow an attacker to cause a denial-of-service condition. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS Siemens reports the vulnerability affects the following products: o SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants): All versions o SINUMERIK 840D sl: All versions 3.2 VULNERABILITY OVERVIEW 3.2.1 UNCONTROLLED RESOURCE CONSUMPTION CWE-400 An attacker may send multiple specially crafted packets to the affected devices, which may cause a denial-of-service condition. A cold restart is required to recover the service. CVE-2020-15783 has been assigned to this vulnerability. A CVSS v3 base score of 5.9 has been calculated; the CVSS vector string is ( AV:N/AC:H/PR:N/UI:N/S:U/ C:N/I:N/A:H ). 3.3 BACKGROUND o CRITICAL INFRASTRUCTURE SECTORS: Chemical, Critical Manufacturing, Food and Agriculture o COUNTRIES/AREAS DEPLOYED: Worldwide o COMPANY HEADQUARTERS LOCATION: Germany 3.4 RESEARCHER WangFangLi from Beijing Winicssec Technology CO reported this vulnerability to Siemens. 4. MITIGATIONS Siemens is preparing updates and recommends users protect network access to Port 102/TCP of affected devices. As a general security measure, Siemens strongly recommends users protect network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends users configure the environment according to Siemens' operational guidelines for Industrial Security and follow the recommendations in the product manuals. Additional information on industrial security by Siemens can be found at: https://www.siemens.com/industrialsecurity For additional information, please refer to Siemens Security Advisory SSA-492828 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.cisa.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.cisa.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. High skill level is needed to exploit. 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: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBX64EKONLKJtyKPYoAQhI5g/9F6/aPRnYLQvEXX+fUYzeTcdv9D1yi7Ps SehPfUOXT2CWLC/BtBfmqUPFsKX0Fd5I4W9OUdFNcWQctd3K0eTkbwfAQ2KcGTRb yG5/sle43LRTAM25gU9Ng/VW6jiwY3uf05JzASLtBSf3yabpmjCqY0UBbapWxoKo vkPsLRVrXW3cLttMbkDPAKG3z8e4NIGaxRF7F7t4UJF+swz6snfTdu/sEa9P3BOg NunIoVbScy0azua1HtkE2HzuXWGI1/uH1UHGjxHdh2E4C3Bz8wZXSsWCxv28jwRW F/aUebey2VT9cHATxjt3sAgt/dIjY9BtdRYluVnpAcPu/impN4W3egnq7D/XyWOU pkGFKpNUf5k6jTsP0uk+nwQOupKUfOVzNVN2qc7Gsf2EfDrQuffZNLJb8z2n2HSc 0xtgnaNNsyfKUPMdgZ8DQxgCmbYrcMwPtt2dhhApgdqJKTjmc7lJYaRMZmrmOAcg cBnMBfEz9fHGn2TfYagZNWO3h23MJ7N/NKW1xS9EWgEHXocAJbhl0FzmkuI14c0g yS0e+0Qlbg49L7WnXMB1ceetNy4moRqqpY6+O/O7KSfzhblv7eu7ZU1zZPwKF38c ZVsA+9xHesHDVIacjVebzcY1VkAkY4Q989yx7gtqjE5cc8UWfuRmUF1IYT7UN5TZ JkgBjuE7Lb8= =FHeE -----END PGP SIGNATURE-----