Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2022.2358 Advisory (icsa-22-132-08) Siemens Industrial Products with OPC UA 13 May 2022 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Siemens Industrial Products with OPC UA Publisher: ICS-CERT Operating System: Network Appliance Resolution: Patch/Upgrade CVE Names: CVE-2021-45117 Original Bulletin: https://us-cert.cisa.gov/ics/advisories/icsa-22-132-08 Comment: CVSS (Max): 6.5 CVE-2021-45117 (CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H) CVSS Source: ICS-CERT Calculator: https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - --------------------------BEGIN INCLUDED TEXT-------------------- ICS Advisory (ICSA-22-132-08) Siemens Industrial Products with OPC UA Original release date: May 12, 2022 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 6.5 o ATTENTION: Exploitable remotely/low attack complexity o Vendor: Siemens o Equipment: SIMATIC NET PC, SITOP Manager, TeleControl Server Basic o Vulnerability: Null Pointer Dereference 2. RISK EVALUATION Successful exploitation of this vulnerability could crash the device by sending uncertain status code in a response message. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS The following Siemens industrial products are affected: o SIMATIC NET PC Software v14: All versions prior to 14 SP1 Update 14 o SIMATIC NET PC Software v15: All versions o SIMATIC NET PC Software v16: All versions o SIMATIC NET PC Software v17: All versions prior to 17 SP1 o SITOP Manager: All versions o TeleControl Server Basic v3: All versions 3.2 VULNERABILITY OVERVIEW 3.2.1 NULL POINTER DEREFERENCE CWE-476 The OPC UA ANSIC stack (also called Legacy C-stack) was reported to crash when an unexpected OPC UA response message status code was accessed via the synchronous Client API. The vulnerability was found in generated code of the OPC Foundation C-stack. An unexpected status code in response messages will result in null pointer dereference, leading to a ping-of-death crash. This affects a client, but it might also affect a server when it uses OpcUa_ClientApi_RegisterServer (e.g., register at Local Discovery Server). A specially crafted UA server or machine-in-the-middle attacker can cause the OPC UA application to crash by sending uncertain status code in response messages. CVE-2021-45117 has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:N/UI:R/S:U/ C:N/I:N/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 has recommended the following: o SIMATIC NET PC Software v14, update to v14 SP1 Update 14 or later o SIMATIC NET PC Software v15, no fix is currently planned o SIMATIC NET PC Software v16, currently no fix is planned o SIMATIC NET PC Software v17, update to v17 SP1 or later o SITOP Manager, no fix is currently planned o TeleControl Server Basic, no fix is currently planned Siemens has identified the following specific workarounds and mitigations to reduce risk: o Do not use OPC client feature to connect via untrusted networks or to untrusted OPC-UA communication partners. o Use VPN for protecting network communication between cells. As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. 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. For additional information, please refer to Siemens Security Advisory SSA-285795 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 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 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. 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/ iQIVAwUBYn2SmMkNZI30y1K9AQgIgQ/+Kd7PmfKmcDBgYl/yydcgKh+hXYkhy2QF +qiaI5xrpwdRJDgBubgWxyk+4Qq+Vd69SxaUYyZNmWbk2IB9wYCTRZ2cTs/6OnDT B2wXEsLYVu72aYfyFfKJZTLQwQy2IoPffLbWOWewQJyLwwYMjxcS/l3qUcdmsmAo crf13E5A3/DDgSk7bOCqtizcY8rYq4vP/2jBFE6AYMM1jnUhRa1+mLGB2X8ZIcWY 9zPUXv2Rn5sT87KNstdsT6P5vNqsa3wKUax6LkrJ2/ma0412SBGGqCW9eVj2jdhQ 29SWjamdS09d3HBRXnIKKFXMv9qR04cM25o12Z1GN0elacN7MIgMuknoDa3e1ukq cSjZgnLVmN271GZlrGKcEy63ajiYBvs2rnJ7YLrhGrAskUYUyJRxkY0p38m1shsi acEK3j5D4lMHFA8VYjsyfK9PlY7dX9yJ1dyRU6Vz8Q6obBtzg3jS9YbY9ATIKKN6 iz5IL5dsLmlu4S+/4S9skPLdN+ibftwPy+Czji7zJN/Jz43oPGZXNaq1ACjXH7wp wPlyJhxj47H6RgncMuZZHgPBDSplzAAfkP3R5ij6h8h7X0k+tQG8zEY4e+EBMstp evzpvNxWMxKcqNBw7keblJt48iXwiA9OejEaHJKJKARN2r2xoN4ACYPPAYnRiHb8 32YhKTDgPPM= =JYaN -----END PGP SIGNATURE-----