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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2021.2405 Advisory (icsa-21-194-10) Siemens RUGGEDCOM ROS 15 July 2021 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Siemens RUGGEDCOM ROS Products Publisher: ICS-CERT Operating System: Network Appliance Impact/Access: Execute Arbitrary Code/Commands -- Remote/Unauthenticated Reduced Security -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2021-31895 Original Bulletin: https://us-cert.cisa.gov/ics/advisories/icsa-21-194-10 - --------------------------BEGIN INCLUDED TEXT-------------------- ICS Advisory (ICSA-21-194-10) Siemens RUGGEDCOM ROS Original release date: July 13, 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 8.1 o ATTENTION : Exploitable remotely o Vendor : Siemens o Equipment : RUGGEDCOM ROS o Vulnerability : Classic Buffer Overflow 2. RISK EVALUATION Successful exploitation of this vulnerability could allow an attacker with network access to an affected device to cause a remote code execution condition. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS The following Siemens products are affected: o RUGGEDCOM ROS i800: All versions prior to 4.3.7 o RUGGEDCOM ROS i801: All versions prior to 4.3.7 o RUGGEDCOM ROS i802: All versions prior to 4.3.7 o RUGGEDCOM ROS i803: All versions prior to 4.3.7 o RUGGEDCOM ROS M969: All versions prior to 4.3.7 o RUGGEDCOM ROS M2100: All versions prior to 4.3.7 o RUGGEDCOM ROS M2200: All versions prior to 4.3.7 o RUGGEDCOM ROS RMC: All versions prior to 4.3.7 o RUGGEDCOM ROS RMC20: All versions prior to 4.3.7 o RUGGEDCOM ROS RMC30: All versions prior to 4.3.7 o RUGGEDCOM ROS RMC40: All versions prior to 4.3.7 o RUGGEDCOM ROS RMC41: All versions prior to 4.3.7 o RUGGEDCOM ROS RMC8388 V4.X: All versions prior to 4.3.7 o RUGGEDCOM ROS RMC8388 V5.X: All versions prior to 5.5.4 o RUGGEDCOM ROS RP110: All versions prior to 4.3.7 o RUGGEDCOM ROS RS400: All versions prior to 4.3.7 o RUGGEDCOM ROS RS401: All versions prior to 4.3.7 o RUGGEDCOM ROS RS416: All versions prior to 4.3.7 o RUGGEDCOM ROS RS416V2 V4.X: All versions prior to 4.3.7 o RUGGEDCOM ROS RS416V2 V5.X: All versions prior to 5.5.4 o RUGGEDCOM ROS RS900 (32M) V4.X: All versions prior to 4.3.7 o RUGGEDCOM ROS RS900 (32M) V5.X: All versions prior to 5.5.4 o RUGGEDCOM ROS RS900G: All versions prior to 4.3.7 o RUGGEDCOM ROS RS900G (32M) V4.X: All versions prior to 4.3.7 o RUGGEDCOM ROS RS900G (32M) V5.X: All versions prior to 5.5.4 o RUGGEDCOM ROS RS900GP: All versions prior to 4.3.7 o RUGGEDCOM ROS RS900L: All versions prior to 4.3.7 o RUGGEDCOM ROS PS900W: All versions prior to 4.3.7 o RUGGEDCOM ROS RS910: All versions prior to 4.3.7 o RUGGEDCOM ROS RS910L: All versions prior to 4.3.7 o RUGGEDCOM ROS RS910W: All versions prior to 4.3.7 o RUGGEDCOM ROS RS920L: All versions prior to 4.3.7 o RUGGEDCOM ROS RS920W: All versions prior to 4.3.7 o RUGGEDCOM ROS RS930L: All versions prior to 4.3.7 o RUGGEDCOM ROS RS930W: All versions prior to 4.3.7 o RUGGEDCOM ROS RS940G: All versions prior to 4.3.7 o RUGGEDCOM ROS RS969: All versions prior to 4.3.7 o RUGGEDCOM ROS RS8000: All versions prior to 4.3.7 o RUGGEDCOM ROS RS8000A: All versions prior to 4.3.7 o RUGGEDCOM ROS RS8000H: All versions prior to 4.3.7 o RUGGEDCOM ROS RS8000T: All versions prior to 4.3.7 o RUGGEDCOM ROS RSG900 V4.X: All versions prior to 4.3.7 o RUGGEDCOM ROS RSG900 V5.X: All versions prior to 5.5.4 o RUGGEDCOM ROS RSG900C: All versions prior to 5.5.4 o RUGGEDCOM ROS RSG900G V4.X: All versions prior to 4.3.7 o RUGGEDCOM ROS RSG800G V5.X: All versions prior to 5.5.4 o RUGGEDCOM ROS RSG900R: All versions prior to 5.5.4 o RUGGEDCOM ROS RSG920P V4.X: All versions prior to 4.3.7 o RUGGEDCOM ROS RSG920P V5.X: All versions prior to 5.5.4 o RUGGEDCOM ROS RSG2100 (32M) V4.X: All versions prior to 4.3.7 o RUGGEDCOM ROS RSG2100 (32M) V5.X: All versions prior to 5.5.4 o RUGGEDCOM ROS RSG2100 V4.X: All versions prior to 4.3.7 o RUGGEDCOM ROS RSG2100P: All versions prior to 4.3.7 o RUGGEDCOM ROS RSG2100P (32M) V4.X: All versions prior to 4.3.7 o RUGGEDCOM ROS RSG2100P (32M) V5.X: All versions prior to 5.5.4 o RUGGEDCOM ROS RSG2200: All versions prior to 4.3.7 o RUGGEDCOM ROS RSG2288 V4.X: All versions prior to 4.3.7 o RUGGEDCOM ROS RSG2288 V5.X: All versions prior to 5.5.4 o RUGGEDCOM ROS RSG2300 V4.X: All versions prior to 4.3.7 o RUGGEDCOM ROS RSG2300 V5.X: All versions prior to 5.5.4 o RUGGEDCOM ROS RSG2300P V4.X: All versions prior to 4.3.7 o RUGGEDCOM ROS RSG2300P V5.X: All versions prior to 5.5.4 o RUGGEDCOM ROS RSG2488 V4.X: All versions prior to 4.3.7 o RUGGEDCOM ROS RSG2488 V5.X: All versions prior to 5.5.4 o RUGGEDCOM ROS RSL910: All versions prior to 5.5.4 o RUGGEDCOM ROS RST916C: All versions prior to 5.5.4 o RUGGEDCOM ROS RST916P: All versions prior to 5.5.4 o RUGGEDCOM ROS RST2228: All versions prior to 5.5.4 3.2 VULNERABILITY OVERVIEW 3.2.1 CLASSIC BUFFER OVERFLOW CWE-120 The DHCP client in affected devices fails to properly sanitize incoming DHCP packets. This could allow an unauthenticated remote attacker to cause memory to be overwritten, potentially allowing remote code execution. CVE-2021-31895 has been assigned to this vulnerability. A CVSS v3 base score of 8.1 has been calculated; the CVSS vector string is ( AV:N/AC:H/PR:N/UI:N/S:U/ C:H/I:H/A:H ). 3.3 BACKGROUND o CRITICAL INFRASTRUCTURE SECTORS : Multiple Sectors o COUNTRIES/AREAS DEPLOYED : Worldwide o COMPANY HEADQUARTERS LOCATION : Germany 3.4 RESEARCHER Siemens reported this vulnerability to CISA. 4. MITIGATIONS Siemens recommends applying updates where applicable: o RUGGEDCOM ROS i800: Update to v4.3.7 or later o RUGGEDCOM ROS i801: Update to v4.3.7 or later o RUGGEDCOM ROS i802: Update to v4.3.7 or later o RUGGEDCOM ROS i803: Update to v4.3.7 or later o RUGGEDCOM ROS M969: Update to v4.3.7 or later o RUGGEDCOM ROS M2100: Update to v4.3.7 or later o RUGGEDCOM ROS M2200: Update to v4.3.7 or later o RUGGEDCOM ROS RMC: Update to v4.3.7 or later o RUGGEDCOM ROS RMC20: Update to v4.3.7 or later o RUGGEDCOM ROS RMC30: Update to v4.3.7 or later o RUGGEDCOM ROS RMC40: Update to v4.3.7 or later o RUGGEDCOM ROS RMC41: Update to v4.3.7 or later o RUGGEDCOM ROS RMC8388 V4.X: Update to v4.3.7 or later o RUGGEDCOM ROS RMC8388 V5.X: Update to v5.5.4 or later o RUGGEDCOM ROS RP110: Update to v4.3.7 or later o RUGGEDCOM ROS RS400: Update to v4.3.7 or later o RUGGEDCOM ROS RS401: Update to v4.3.7 or later o RUGGEDCOM ROS RS416: Update to v4.3.7 or later o RUGGEDCOM ROS RS416V2 V4.X: Update to v4.3.7 or later o RUGGEDCOM ROS RS416V2 V5.X: Update to v5.5.4 or later o RUGGEDCOM ROS RS900 (32M) V4.X: Update to v4.3.7 or later o RUGGEDCOM ROS RS900 (32M) V5.X: Update to v5.5.4 or later o RUGGEDCOM ROS RS900G: Update to v4.3.7 or later o RUGGEDCOM ROS RS900G (32M) V4.X: Update to v4.3.7 or later o RUGGEDCOM ROS RS900G (32M) V5.X: Update to v5.5.4 or later o RUGGEDCOM ROS RS900GP: Update to v4.3.7 or later o RUGGEDCOM ROS RS900L: Update to v4.3.7 or later o RUGGEDCOM ROS PS900W: Update to v4.3.7 or later o RUGGEDCOM ROS RS910: Update to v4.3.7 or later o RUGGEDCOM ROS RS910L: Update to v4.3.7 or later o RUGGEDCOM ROS RS910W: Update to v4.3.7 or later o RUGGEDCOM ROS RS920L: Update to v4.3.7 or later o RUGGEDCOM ROS RS920W: Update to v4.3.7 or later o RUGGEDCOM ROS RS930L: Update to v4.3.7 or later o RUGGEDCOM ROS RS930W: Update to v4.3.7 or later o RUGGEDCOM ROS RS940G: Update to v4.3.7 or later o RUGGEDCOM ROS RS969: Update to v4.3.7 or later o RUGGEDCOM ROS RS8000: Update to v4.3.7 or later o RUGGEDCOM ROS RS8000A: Update to v4.3.7 or later o RUGGEDCOM ROS RS8000H: Update to v4.3.7 or later o RUGGEDCOM ROS RS8000T: Update to v4.3.7 or later o RUGGEDCOM ROS RSG900 V4.X: Update to v4.3.7 or later o RUGGEDCOM ROS RSG900 V5.X: Update to v5.5.4 or later o RUGGEDCOM ROS RSG900C: Update to v5.5.4 or later o RUGGEDCOM ROS RSG900G V4.X: Update to v4.3.7 or later o RUGGEDCOM ROS RSG800G V5.X: Update to v5.5.4 or later o RUGGEDCOM ROS RSG900R: Update to v5.5.4 or later o RUGGEDCOM ROS RSG920P V4.X: Update to v4.3.7 or later o RUGGEDCOM ROS RSG920P V5.X: Update to v5.5.4 or later o RUGGEDCOM ROS RSG2100 (32M) V4.X: Update to v4.3.7 or later o RUGGEDCOM ROS RSG2100 (32M) V5.X: Update to v5.5.4 or later o RUGGEDCOM ROS RSG2100 V4.X: Update to v4.3.7 or later o RUGGEDCOM ROS RSG2100P: Update to v4.3.7 or later o RUGGEDCOM ROS RSG2100P (32M) V4.X: Update to v4.3.7 or later o RUGGEDCOM ROS RSG2100P (32M) V5.X: Update to v5.5.4 or later o RUGGEDCOM ROS RSG2200: Update to v4.3.7 or later o RUGGEDCOM ROS RSG2288 V4.X: Update to v4.3.7 or later o RUGGEDCOM ROS RSG2288 V5.X: Update to v5.5.4 or later o RUGGEDCOM ROS RSG2300 V4.X: Update to v4.3.7 or later o RUGGEDCOM ROS RSG2300 V5.X: Update to v5.5.4 or later o RUGGEDCOM ROS RSG2300P V4.X: Update to v4.3.7 or later o RUGGEDCOM ROS RSG2300P V5.X: Update to v5.5.4 or later o RUGGEDCOM ROS RSG2488 V4.X: Update to v4.3.7 or later o RUGGEDCOM ROS RSG2488 V5.X: Update to v5.5.4 or later o RUGGEDCOM ROS RSL910: Update to v5.5. 4 or later o RUGGEDCOM ROS RST916C: Update to v5.5.4 or later o RUGGEDCOM ROS RST916P: Update to v5.5.4 or later o RUGGEDCOM ROS RST2228: Update to v5.5.4 or later Siemens has identified the following specific workarounds and mitigations users can apply to reduce the risk: o Enabling DHCP snooping ensures the DHCP client in the affected devices will only accept DHCP requests from trusted DHCP servers o Disable DHCP and configure a static IP address to the device 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 the Siemens Operational Guidelines for Industrial Security and following the recommendations in the product manuals. For additional information, please refer to Siemens Security Advisory SSA-373591 . 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. This vulnerability has a high attack complexity. 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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On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBYO+ZUONLKJtyKPYoAQhQoA//T3oAbRfxfbZndkqbB5EL8oidpILJFSdw 1tAY011LBm96uITKSR+79BQ6rC/8CR7yeG2OaU2R8F1uKfmY6vYYu2qarzLwEu7X LVRHBriIuYhoRBJSV2wTeWymGRKGRX4zWPT9jCwwnzxokSDOYnxT39mEnXIdz4Zf sFIXWAniIgMA03XMUOHOpTNY3v1zYpH7lgBJnAkDbBgYzpQzwuIsMX7hpMZ3CPGg yKoBKOXJs2QtXLfRdscmKCv5AFiYlct4A3vz07XhTDpDWnSF+qK/aWICP5hO7rXK 7AxRkIQW/l9iDAaej6EYdf5GZ9WefJY/UMpXje9g6fM9IUOjK7yH3wDgNP2+fI2M MPrR3KRSHS3R8rcsVy9SPHjMmTSCUdlY9O8gXyPzg2NTSA5k+7Ns/s2r8hvp1oKX k9V3FFSd5w1I+Kduf7HUWcqhPbegppc0Xq5G9UngFOmf+WVwtiMpeNzFESbO7xXY 4mZXGTWvjSY5bxJErYd0fVxkuqq0n2id2oXVUT7SOAsDakhs5klbLMJ8fHX7QQTt EZdVLgrNaXXWDWGcTNyzcu712dMzrdKgg1nTfvIhLmlZoqMKEQ9v7GfnUNXK3n5/ t8PE5WXg6ZGstWVlt9kcaDs/5O3L0zJ6DC6ENHamkU0DdUyCyHZ1fluDCOF2OyD7 a3f4EZkYTG4= =ZLSe -----END PGP SIGNATURE-----