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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2016.2799 Siemens SIMATIC CP 1543-1 Vulnerabilities and Siemens SIMATIC CP 343-1/CP 443-1 Modules and SIMATIC S7-300/S7-400 CPUs Vulnerabilities 23 November 2016 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: SIMATIC CP 1543-1 SIMATIC CP 343-1 SIMATIC CP 443-1 SIMATIC S7-300 SIMATIC S7-400 Publisher: ICS-CERT Operating System: Network Appliance Impact/Access: Execute Arbitrary Code/Commands -- Remote with User Interaction Access Privileged Data -- Remote/Unauthenticated Increased Privileges -- Existing Account Denial of Service -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2016-8673 CVE-2016-8672 CVE-2016-8562 CVE-2016-8561 Original Bulletin: https://ics-cert.us-cert.gov/advisories/ICSA-16-327-01 https://ics-cert.us-cert.gov/advisories/ICSA-16-327-02 Comment: This bulletin contains two (2) ICS-CERT security advisories. - --------------------------BEGIN INCLUDED TEXT-------------------- Advisory (ICSA-16-327-01) Siemens SIMATIC CP 1543-1 Vulnerabilities Original release date: November 22, 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 Siemens has released an advisory to inform its users how to mitigate vulnerabilities that affect SIMATIC CP 1543-1. These vulnerabilities were coordinated directly with Siemens by SOGETI and Agence nationale de la sécurité des systèmes d'information (ANSSI). Siemens has produced a firmware to mitigate these vulnerabilities. These vulnerabilities could be exploited remotely. AFFECTED PRODUCTS Siemens reports that the vulnerabilities affect the following versions of SIMATIC CP 1543-1: SIMATIC CP 1543-1: All versions prior to V2.0.28 IMPACT An attacker who exploits these vulnerabilities may be able to elevate privileges on the affected devices or cause a denial-of-service condition. Impact to individual organizations depends on many factors that are unique to each organization. NCCIC/ICS-CERT recommends that organizations evaluate the impact of these vulnerabilities based on their operational environment, architecture, and product implementation. BACKGROUND Siemens is a multinational company headquartered in Munich, Germany. The affected product, SIMATIC CP 1543-1 communication processor, connects the S7-1500 controller to Ethernet networks. It provides integrated security functions, such as firewall and virtual private networks (VPNs), and supports other protocols with data encryption such as FTP. The communication processor protects S7-1500 stations against unauthorized access, as well as integrity and confidentiality of transmitted data. According to Siemens, this product is 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 INPUT VALIDATION[a] Users with elevated privileges to TIA-Portal and project data on the engineering station could possibly get privileged access on affected devices. CVE-2016-8561[b] has been assigned to this vulnerability. A CVSS v3 base score of 6.6 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H).[c] IMPROPER PRIVILEGE MANAGEMENT[d] Under special conditions, it may be possible to write SNMP variables on Port 161/UDP that should be read-only and should only be configured with TIA-Portal. A write to these variables could reduce the availability or cause a denial of service. CVE-2016-8562[e] has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H).[f] VULNERABILITY DETAILS EXPLOITABILITY These vulnerabilities could be exploited remotely. EXISTENCE OF EXPLOIT No known public exploits specifically target these vulnerabilities. DIFFICULTY Crafting a working exploit for these vulnerabilities would be difficult. MITIGATION Siemens provides firmware update V2.0.28 for SIMATIC CP 1543-1 devices, which fixes the vulnerabilities, and recommends users update to the new version. This update can be found on the Siemens web site at the following location: https://support.industry.siemens.com/cs/ww/en/view/109743137 (link is external) Siemens strongly recommends users protect network access to the management interface of perimeter devices with appropriate mechanisms. Siemens also advises that users configure the operational environment according to Siemens' Operational Guidelines for Industrial Security: https://www.siemens.com/cert/operational-guidelines-industrial-security (link is external) For more information on this vulnerability and more detailed mitigation instructions, please see Siemens Security Advisory SSA-672373 at the following location: http://www.siemens.com/cert/advisories (link is external) ICS-CERT recommends that users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Specifically, users should: Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet. Locate control system networks and remote devices behind firewalls, and isolate them from the business network. 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. 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-20: Improper Input Validation, https://cwe.mitre.org/data/definitions/20.html, web site last accessed November 22, 2016. b. NVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-8561, web site last accessed November 22, 2016. c. CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S..., web site last accessed November 22, 2016. d. CWE-269: Improper Privilege Management, https://cwe.mitre.org/data/definitions/269.html, web site last accessed November 22, 2016. e. NVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-8562, web site last accessed November 22, 2016. f. CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S..., web site last accessed November 22, 2016. Contact Information For any questions related to this report, please contact ICS-CERT at: Email: ics-cert@hq.dhs.gov (link sends e-mail) 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. - --- Advisory (ICSA-16-327-02) Siemens SIMATIC CP 343-1/CP 443-1 Modules and SIMATIC S7-300/S7-400 CPUs Vulnerabilities Original release date: November 22, 2016 Print Document 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 Siemens has released an advisory regarding vulnerabilities affecting SIMATIC CP 343-1 Advanced/CP-443-1 Advanced devices and SIMATIC S7-300/S7-400 CPUs. Inverse Path auditors and the Airbus ICT Industrial Security team reported these vulnerabilities directly to Siemens. Siemens has made new firmware versions available for several products and a temporary fix for the remaining affected products to mitigate these vulnerabilities. These vulnerabilities could be exploited remotely. AFFECTED PRODUCTS Siemens reports that the vulnerabilities affect the following SIMATIC products: SIMATIC CP 343-1 Advanced: All versions prior to V3.0.53, SIMATIC CP 443-1 Advanced: All versions, SIMATIC S7-300 CPU family: All firmware versions, and SIMATIC S7-400 CPU family: All firmware versions. IMPACT Under certain conditions, an attacker could use these vulnerabilities to perform operations as an authenticated user. Impact to individual organizations depends on many factors that are unique to each organization. NCCIC/ICS-CERT recommends that organizations evaluate the impact of these vulnerabilities based on their operational environment, architecture, and product implementation. BACKGROUND Siemens is a multinational company headquartered in Munich, Germany. Communication Processor (CP) modules SIMATIC CP 343-1 Advanced and CP 443-1 Advanced are designed to enable SIMATIC S7-300/S7-400 CPUs to communicate via Ethernet. According to Siemens, several critical infrastructure (CI) sectors deploy these products, including Chemical, Critical Manufacturing, and Food and Agriculture. Siemens estimates that users of these products are located worldwide. VULNERABILITY CHARACTERIZATION VULNERABILITY OVERVIEW INSUFFICIENT VERIFICATION OF DATA AUTHENTICITY[a] The integrated web server at Port 80/TCP or Port 443/TCP of the affected devices could allow remote attackers to perform actions with the permissions of an authenticated user, provided the targeted user has an active session and is induced to trigger the malicious request. CVE-2016-8673[b] has been assigned to this vulnerability. A CVSS v3 base score of 6.3 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L).[c] SENSITIVE COOKIE IN HTTPS SESSION WITHOUT 'SECURE' ATTRIBUTE[d] The integrated web server delivers cookies without the "secure" flag. Modern browsers interpreting the flag would mitigate potential data leakage in case of clear text transmission. CVE-2016-8672[e] has been assigned to this vulnerability. A CVSS v3 base score of 4.0 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N).[f] VULNERABILITY DETAILS EXPLOITABILITY These vulnerabilities could be exploited remotely. EXISTENCE OF EXPLOIT No known public exploits specifically target these vulnerabilities. DIFFICULTY An attacker with a low skill may be able to exploit these vulnerabilities. MITIGATION Siemens provides firmware versions that fix the vulnerabilities and recommends that users update to the fixed versions: SIMATIC CP 343-1 Advanced: Update to V3.0.53: https://support.industry.siemens.com/cs/ww/en/view/109742236 (link is external) For SIMATIC CP 443-1 Advanced devices, Siemens recommends the following mitigations: Restrict web server access to the internal network, Use VPN for protecting network communication on the external network interface, and Follow operational guidelines. For SIMATIC S7-300/S7-400 CPUs, Siemens recommends the following mitigations: Apply cell protection concept, Use VPN for protecting network communication between cells, and Apply Defense-in-Depth. Siemens strongly recommends users protect network access to SIMATIC S7-300/S7-400 CPUs and to the web interface of SIMATIC CP 343-1 Advanced and CP 443-1 Advanced devices with appropriate mechanisms. Siemens also advises that users configure the protected operational environment according to Siemens' Operational Guidelines for Industrial Security: https://www.siemens.com/cert/operational-guidelines-industrial-security (link is external) For more information on this vulnerability and more detailed mitigation instructions, please see Siemens Security Advisory SSA-603476 at the following location: http://www.siemens.com/cert/advisories (link is external) Siemens will update SSA-603476 and ICS-CERT will update this advisory when new information becomes available. ICS-CERT recommends that users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Specifically, users should: Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet. Locate control system networks and remote devices behind firewalls, and isolate them from the business network. 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. 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-345: Insufficient Verification of Data Authenticity, https://cwe.mitre.org/data/definitions/345.html, web site last accessed November 22, 2016. b. NVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-8673, 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:L/PR:N/UI:R/S..., web site last accessed November 22, 2016. d. CWE-614: Sensitive Cookie in HTTPS Session Without 'Secure' Attribute, https://cwe.mitre.org/data/definitions/614.html, web site last accessed November 22, 2016. e. NVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-8672, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory. f. CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S..., web site last accessed November 22, 2016. Contact Information For any questions related to this report, please contact ICS-CERT at: Email: ics-cert@hq.dhs.gov (link sends e-mail) 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. 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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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