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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2020.1344.2 ICS Advisory (ICSA-20-105-07) Siemens SCALANCE & SIMATIC 13 January 2021 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Siemens SCALANCE Siemens SIMATIC Publisher: ICS-CERT Operating System: Network Appliance Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: None CVE Names: CVE-2019-19301 Original Bulletin: https://www.us-cert.gov/ics/advisories/icsa-20-105-07 Revision History: January 13 2021: Updated products affected and mitigation details April 17 2020: Initial Release - --------------------------BEGIN INCLUDED TEXT-------------------- ICS Advisory (ICSA-20-105-07) Siemens SCALANCE & SIMATIC (Update C) Original release date: January 12, 2021 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 7.5 o ATTENTION: Exploitable remotely/low skill level to exploit o Vendor: Siemens o Equipment: SCALANCE, SIMATIC o Vulnerability: Resource Exhaustion 2. UPDATE INFORMATION This updated advisory is a follow-up to the advisory update titled ICSA-20-105-07 Siemens SCALANCE & SIMATIC (Update B) that was published September 8, 2020, to the ICS webpage on us-cert.cisa.gov. 3. RISK EVALUATION Successful exploitation of this vulnerability can result in a denial-of-service condition. 4. TECHNICAL DETAILS 4.1 AFFECTED PRODUCTS The following versions of SCALANCE are affected: o SCALANCE X-200 switch family (incl. SIPLUS NET variants): all versions o SCALANCE X-200IRT switch family (incl. SIPLUS NET variants): all versions o SCALANCE X-300 switch family (incl. X408 and SIPLUS NET variants): all versions - --------- Begin Update C Part 1 of 2 --------- o [S: SCALANCE S602: all versions :S] o [S: SCALANCE S612: all versions :S] o [S: SCALANCE S623: all versions :S] o [S: SCALANCE S627-2M: all versions :S] - --------- End Update C Part 1 of 2 --------- The following versions of SIMATIC are affected: o SIMATIC CP 443-1 (incl. SIPLUS NET variants): all versions o SIMATIC CP 443-1 Advanced (incl. SIPLUS NET variants): all versions o SIMATIC RF180C: all versions o SIMATIC RF182C: all versions 4.2 VULNERABILITY OVERVIEW 4.2.1 UNCONTROLLED RESOURCE CONSUMPTION ('RESOURCE EXHAUSTION') CWE-400 The VxWorks-based Profinet TCP stack can be forced to make resource-intense calls for every incoming packet, which can lead to a denial-of-service condition. CVE-2019-19301 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 ). 4.3 BACKGROUND o CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing o COUNTRIES/AREAS DEPLOYED: Worldwide o COMPANY HEADQUARTERS LOCATION: Germany 4.4 RESEARCHER 5. MITIGATIONS Siemens has identified the following specific workarounds and mitigations users can apply to reduce the risk: - --------- Begin Update C Part 2 of 2 --------- o [S: For SCALANCE S-600 family (S602, S612, S623, S627-2M): migrate to a successor product within the SCALANCE SC-600 family, v2.1 or later version. For details refer to the notice of discontinuation . :S] - --------- End Update C Part 2 of 2 --------- o For SIMATIC RF180C and RF182C: migrate to a successor product within the SIMATIC RF18xC/CI family v1.3 or later version. For details refer to the notice of discontinuation . o In all other cases please follow the General Security Recommendations. Additional information on industrial security by Siemens can be found at: https://www.siemens.com/industrialsecurity For further inquiries on security vulnerabilities in Siemens products and solutions, please contact Siemens ProductCERT . For more information on this vulnerability, please see Siemens security advisory SSA-102233 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. 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. 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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). 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