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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2017.2188.2 Advisory (ICSA-17-243-01) Siemens industrial products using the Discovery Service of the OPC UA protocol stack by the OPC foundation 4 October 2017 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: SIMATIC PCS 7 SIMATIC WinCC SIMATIC NET PC Software SIMATIC IT Production Suite Publisher: ICS-CERT Operating System: Windows Network Appliance Impact/Access: Denial of Service -- Remote/Unauthenticated Access Confidential Data -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2017-12069 Original Bulletin: https://ics-cert.us-cert.gov/advisories/ICSA-17-243-01 Revision History: October 4 2017: Updated Product and Mitigation September 1 2017: Initial Release - --------------------------BEGIN INCLUDED TEXT-------------------- Advisory (ICSA-17-243-01A) Siemens Industrial products using the Discovery Service of the OPC UA protocol stack by the OPC foundation Original release date: October 03, 2017 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/. CVSS v3 8.2 ATTENTION: Remotely exploitable/low skill level to exploit. Vendor: Siemens Equipment: Industrial products using the Discovery Service of the OPC UA protocol stack by the OPC foundation Vulnerability: Improper Restriction of XML External Entity Reference UPDATE INFORMATION This updated advisory is a follow-up to the original advisory titled ICSA-17-242-01 Siemens Industrial products using the Discovery Service of the OPC UA protocol stack by the OPC foundation that was published August 31, 2017, on the NCCIC/ICS-CERT web site. AFFECTED PRODUCTS - --------- Begin Update A Part 1 of 2 -------- Siemens reports that the vulnerability affects the following industrial products, which use the Discovery Service of the OPC UA protocol stack by the OPC foundation: SIMATIC PCS 7 V8.0: All versions V8.1: All versions SIMATIC WinCC: V7.2: All versions SIMATIC WinCC Runtime Professional: V13: All versions V14: All versions prior to V14 SP1 SIMATIC NET PC Software: All versions SIMATIC IT Production Suite: All versions prior to V6.5 - --------- End Update A Part 1 of 2 -------- IMPACT Successful exploitation of this vulnerability may allow an attacker to access various resources. MITIGATION - --------- Begin Update A Part 2 of 2 -------- Siemens provides fixes for the following products and recommends users upgrade to the newest version: SIMATIC PCS 7: All affected versions: Follow FAQ: https://support.industry.siemens.com/cs/ww/en/view/109749461 (link is external) SIMATIC WinCC: All versions: Follow FAQ to turn off the service after commissioning: https://support.industry.siemens.com/cs/ww/en/view/109749461 (link is external) SIMATIC WinCC Runtime Professional: Update to V14 SP1 https://support.industry.siemens.com/cs/ww/en/view/109746276 (link is external) All other versions: Follow FAQ to turn off the service after commissioning: https://support.industry.siemens.com/cs/ww/en/view/109749461 (link is external) SIMATIC NET PC Software: Follow FAQ to turn off the service after commissioning: https://support.industry.siemens.com/cs/ww/en/view/109749461 (link is external) - --------- End Update A Part 2 of 2 -------- Siemens is preparing further updates and recommends the following mitigations in the meantime: Turn off the Discovery Service or block it on the local firewall, Apply cell protection concept, Use VPN for protecting network communication between cells, and Apply Defense in Depth. Siemens recommends users protect network access with appropriate mechanisms such as firewalls, segmentation, and VPNs. 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-535640 at the following location: http://www.siemens.com/cert/advisories (link is external) The OPC Foundation also published a security bulletin for this vulnerability: https://opcfoundation-onlineapplications.org/faq/SecurityBulletins/OPC_Foundation_Security_Bulletin_CVE-2017-12069.pdf ICS-CERT recommends that users take defensive measures to minimize the risk of exploitation of this vulnerability. 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 ICSCERT 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. No known public exploits specifically target this vulnerability. VULNERABILITY OVERVIEW IMPROPER RESTRICTION OF XML EXTERNAL ENTITY REFERENCE ('XXE') CWE-611 By sending specially crafted packets to the OPC Discovery Server at Port 4840/TCP, an attacker might cause the system to access various resources chosen by the attacker. CVE-2017-12069 has been assigned to this vulnerability. A CVSS v3 base score of 8.2 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H). RESEARCHER Sergey Temnikov of Kaspersky Lab reported this vulnerability to Siemens. BACKGROUND Critical Infrastructure Sectors: Chemical, Energy, Food and Agriculture, Water and Wastewater Systems Countries/Areas Deployed: Worldwide Company Headquarters Location: Germany - --------------------------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). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBWdReZYx+lLeg9Ub1AQhJbQ/+Px/iJkf9sf7V4ErwInBsvSEmv8zst8Pb 8XGPdwGsEPtnGdVySmgt1uxNXhvh/4tXi2V5uhRSYxcVHccDneka1FigVDORIfME kXs9fwfJxQNKdjTG6//LTafUlKqJLVZ4jQJeSg3kgjRL2PnomrvtfEwA4BaXkiCl jH45MMdvMSa7B8Gc7QGGBR4+y8jJRlHo3YEbdKIFi9eFhjYl+y3Kl9WhXDrW/+RG +0TA9X9sut2whn/dPP4lZBjnsswW3GdUWpmqu9BWZzoPo5O71mqXt17CleuWnS4f 8qyxNm/KUy55M/wVQFR+4gX4w375Qldz6DiQsmohhj8u3x6USGHO4GNs77MSnreG Xv1lSaAbAwLC3t1KaQsUY8e341oVci1DPpNgY/ogfhw8b5dPTdb4r4j4wYZamcKH w74Gzx/bqVvXb4Ig0kauHDW31N+KeGxkvvSWKcDDb1l5mgKky3suU8HU1MPIhMQE FX1LDGxesGv+AkJdhXT6sTPW1tkmhmJftG/vqcG18ziR3C2IFS60D7OEfGCJ6Oun ro7mEjwhZJ1nrryaHMVyexaofpz3iNVsrIcLT0pIodZ/DH5uR56sxSR+bYJ2+jEn CNQUBeia4ycFxpXNnQd7ES0ZlsDiTbIWFGl44yEdXndSSonbF6eqdiZr8RLFQ3Bw wJCs76kivZ0= =0FNg -----END PGP SIGNATURE-----