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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2016.2982 Siemens SIMATIC WinCC and SIMATIC PCS 7 ActiveX Vulnerability 15 December 2016 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Siemens SIMATIC WinCC Siemens SIMATIC PCS 7 Publisher: ICS-CERT Operating System: Windows Network Appliance Impact/Access: Denial of Service -- Remote with User Interaction Access Confidential Data -- Remote with User Interaction Resolution: Patch/Upgrade CVE Names: CVE-2016-9160 Original Bulletin: https://ics-cert.us-cert.gov/advisories/ICSA-16-348-04 - --------------------------BEGIN INCLUDED TEXT-------------------- Advisory (ICSA-16-348-04) Siemens SIMATIC WinCC and SIMATIC PCS 7 ActiveX Vulnerability Original release date: December 13, 2016 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/. OVERVIEW Mingzheng Li from Acorn Network Security Lab has identified an ActiveX vulnerability in Siemens SIMATIC WinCC and SIMATIC PCS 7. Siemens has produced a new version to mitigate this vulnerability. This vulnerability could be exploited remotely. AFFECTED PRODUCTS Siemens reports that the vulnerability affects the following versions of SIMATIC: SIMATIC WinCC: All versions prior to SIMATIC WinCC V7.2, and SIMATIC PCS 7: All versions prior to SIMATIC PCS 7 V8.0 SP1 IMPACT Exploitation of this vulnerability may allow an attacker to crash the component or leak application memory content. Impact to individual organizations depends on many factors that are unique to each organization. NCCIC/ICS-CERT recommends that organizations evaluate the impact of this vulnerability based on their operational environment, architecture, and product implementation. BACKGROUND Siemens is a multinational company headquartered in Munich, Germany. The affected products are: SIMATIC WinCC, a supervisory control and data acquisition (SCADA) system; and SIMATIC PCS7, a distributed control system (DCS) integrating SIMATIC WinCC. These products are deployed across several sectors including Chemical, Energy, Food and Agriculture, and Water and Wastewater Systems. Siemens estimates that these products are used worldwide. VULNERABILITY CHARACTERIZATION VULNERABILITY OVERVIEW IMPROPER RESTRICTION OF OPERATIONS WITHIN THE BOUNDS OF A MEMORY BUFFER[a] An attacker could crash an ActiveX component or leak parts of the application memory if a user is tricked into clicking on a malicious link under certain conditions. An attacker must have control over a web site that is allowed to execute ActiveX components. CVE-2016-9160[b] has been assigned to this vulnerability. A CVSS v3 base score of 4.2 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:L).[c] VULNERABILITY DETAILS EXPLOITABILITY This vulnerability is not exploitable remotely and cannot be exploited without user interaction. The exploit is only triggered when a local user is social engineered into clicking on a malicious link. EXISTENCE OF EXPLOIT No known public exploits specifically target this vulnerability. DIFFICULTY Crafting a working exploit for this vulnerability would be difficult. Social engineering is required to convince the user to click on the malicious link. MITIGATION Siemens provides SIMATIC WinCC Version 7.2 and newer, and PCS7 Version 8.0 SP2 and newer, which fix the vulnerability. Users can obtain these newer versions by contacting the local Siemens representative or customer support at: https://w3.siemens.com/aspa_app/ Until users can upgrade to the new versions, Siemens recommends the following mitigations to reduce the risk: Only allow execution of ActiveX components on trusted sites. Apply defense-in-depth concepts. For more information on this vulnerability and more detailed mitigation instructions, please see Siemens Security Advisory SSA-693129 at the following location: http://www.siemens.com/cert/en/cert-security-advisories.htm Siemens advises configuring the environment according to Siemens operational guidelines in order to run the devices in a protected IT environment. https://www.siemens.com/cert/operational-guidelines-industrial-security ICS-CERT recommends that users take the following measures to protect themselves from social engineering attacks: Do not click web links or open unsolicited attachments in email messages. Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. ICS-CERT reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. ICS-CERT also provides a section for control systems security recommended practices on the ICS-CERT web page. 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 in the ICS-CERT Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies, that is available for download from the ICS-CERT web site. Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to ICS-CERT for tracking and correlation against other incidents. a. CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer, https://cwe.mitre.org/data/definitions/119.html, web site last accessed December 13, 2016. b. NVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-9160, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory. c. CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S..., web site last accessed December 13, 2016. Contact Information For any questions related to this report, please contact ICS-CERT at: Email: ics-cert@hq.dhs.gov Toll Free: 1-877-776-7585 International Callers: (208) 526-0900 For industrial control systems security information and incident reporting: http://ics-cert.us-cert.gov ICS-CERT 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: http://www.auscert.org.au/render.html?cid=1980 =========================================================================== 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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