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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2018.3062 Advisory (ICSA-18-282-05) Siemens SIMATIC S7-1500, SIMATIC S7-1500 Software Controller and SIMATIC ET 200SP Open Controller 10 October 2018 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Siemens Simatic S7-1500 Siemens Simatic ET 200SP Publisher: ICS-CERT Operating System: Network Appliance Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2018-13805 Original Bulletin: https://ics-cert.us-cert.gov/advisories/ICSA-18-282-05 - --------------------------BEGIN INCLUDED TEXT-------------------- Advisory (ICSA-18-282-05) Siemens SIMATIC S7-1500, SIMATIC S7-1500 Software Controller and SIMATIC ET 200SP Open Controller Original release date: October 09, 2018 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/. 1. EXECUTIVE SUMMARY o CVSS v3 5.3 o ATTENTION: Exploitable remotely/low skill level to exploit o Vendor: Siemens o Equipment: SIMATIC S7-1500, SIMATIC S7-1500 Software Controller and SIMATIC ET 200SP Open Controller o Vulnerability: Denial of Service from improper input validation 2. RISK EVALUATION An attacker with network access to the PLC may be able to cause a denial-of-service condition on the network stack. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS Siemens reports that this vulnerability affects the following products and versions: o Simatic S7-1500 (incl. F), all versions prior to v2.5 down to and including v2.0 o Simatic S7-1500 Software Controller all versions prior to v2.5 down to and including v2.0 o Simatic ET 200SP Open Controller all versions including and after v2.0 3.2 VULNERABILITY OVERVIEW 3.2.1 IMPROPER INPUT VALIDATION CWE-20 An attacker can cause a denial-of-service condition on the network stack by sending a large number of specially crafted packets to the PLC. The PLC will lose its ability to communicate over the network. This vulnerability could be exploited by an attacker with network access to the affected systems. Successful exploitation requires no privileges and no user interaction. An attacker could use this vulnerability to compromise availability of the network connectivity. CVE-2018-13805 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:L/PR:N/UI:N/S:U /C:N/I:N/A:L). 3.3 BACKGROUND o CRITICAL INFRASTRUCTURE SECTORS: Chemical, Critical Manufacturing, Energy, Food and Agriculture, Water and Wastewater Systems o COUNTRIES/AREAS DEPLOYED: Worldwide o COMPANY HEADQUARTERS LOCATION: Germany 3.4 RESEARCHER Marcin Dudek, Jacek Gajewski, Kinga Staszkiewicz, Jakub Suchorab, and Joanna Walkiewicz from National Centre for Nuclear Research Poland reported this vulnerability to Siemens. 4. MITIGATIONS Siemens provides updates to address this vulnerability in these products and recommends users update to the new version. o SIMATIC S7-1500 Software Controller: Update to v2.5 or newer: https://support.industry.siemens.com/cs/us/en/view/109478528 o SIMATIC S7-1500 incl. F: Update to v2.5 or newer: https://support.industry.siemens.com/cs/us/en/ps/13717/dl Siemens has identified the following specific workarounds and mitigations users can apply to reduce the risk: o Restrict network access to affected devices o Apply cell-protection concept o Apply defense-in-depth 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 Siemens' operational guidelines for industrial security (https:// www.siemens.com/cert/operational-guidelines-industrial-security), and following the recommendations in the product manuals. Additional information on Industrial Security by Siemens can be found at: https://www.siemens.com/industrialsecurity For more information on this vulnerability and associated software updates, please see Siemens security advisory SSA-347726 on their website: https://www.siemens.com/cert/advisories NCCIC 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. NCCIC reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. NCCIC 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 on the ICS-CERT website 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 NCCIC for tracking and correlation against other incidents. No known public exploits specifically target this vulnerability. - --------------------------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: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBW72ACmaOgq3Tt24GAQioeg/8DeluJky1LJeJ9F8wJPlMpZe/xB96fkEu 4oi5TUw8RiFfGVdYAoxoGfoxXHWUCqKNhNWsPNa+efmKUqmTPWyCk9QDzqoC8As3 BXCNRLRJHnzi9JizaJSs76I7nyGUTLJUCEcQotDPfOoQG9HA+rs/7blkBneg4/bO f0+TorI3H3IVZWl1onsDNwsCXXFnXURGVNYhCBB5tDsxiQZ/kNSll0l2fbPnRbhr 8HebnEML4zW/8EVbjch5O/xHUw1CrTk3r7OtRK0vLcDE517H8xfbllebbfIjv0HJ w4dXLE3/t/xMMuL6RjANQkUGrpFpt4pBdAlDcmCXvTwajCLfKJwUo0VKSDsZriXL b4ZIrUPGoThkloIzHljViTKmMWNmxJFBgZ3FqUDTf2DIQ9eNzGa/RzmTIc/d8/bf gUhkgfaCdIztV/zmaiF7iqjX7KJtFcsnLOljx6l+NxSiHx7Pnfi/eJQYcuTkrzMV ctPMgZdSMDd6P+5AqrXE5/lcyNr577vkr1vAznXLz8sDMldV8s9F5m27vwKQ1MnB vSXWOvUZWLfH6ct+cE4EjBy63IxmEkqcFxglLsKIuZm5hkBDq2VjWbVQF40VfeVY ZeOMMFwwxjCXRyB9zu7LOB7ljIIUy7RYKIsuSVF5wbeW0moITOq9JMtobSGsewRX kueAwnUiT2Q= =0ufk -----END PGP SIGNATURE-----