22 July 2015
Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2015.1913 Advisory (ICSA-15-202-01) Siemens SIPROTEC Denial-of-Service Vulnerability 22 July 2015 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Siemens SIPROTEC Publisher: US-CERT Operating System: Network Appliance Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2015-5374 Original Bulletin: https://ics-cert.us-cert.gov/advisories/ICSA-15-202-01 - --------------------------BEGIN INCLUDED TEXT-------------------- Advisory (ICSA-15-202-01) Siemens SIPROTEC Denial-of-Service Vulnerability Original release date: July 21, 2015 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 identified a denial-of-service vulnerability in the SIPROTEC 4 and SIPROTEC Compact devices. This vulnerability was reported directly to Siemens by Victor Nikitin from iGrids LLC Russia. Siemens has produced a new firmware update to mitigate this vulnerability. This vulnerability could be exploited remotely. AFFECTED PRODUCTS Siemens reports that the vulnerability affects the following versions: SIPROTEC 4 and SIPROTEC Compact product families All devices that include the EN100 Ethernet module version V4.24 or prior. IMPACT An attacker could remotely cause a denial of service by exploiting this vulnerability. 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, SIPROTEC 4 and SIPROTEC Compact devices, provide a wide range of integrated protection, control, measurement, and automation functions for electrical substations and other fields of application. The EN100 module is used for enabling IEC 61850 communications with electrical/optical 100 Mbit interface for SIPROTEC 4 and SIPROTEC Compact devices. According to Siemens, SIPROTEC devices are deployed across several sectors including Energy. Siemens estimates that these products are used worldwide. VULNERABILITY CHARACTERIZATION VULNERABILITY OVERVIEW DENIAL OF SERVICE [a] Specially crafted packets sent to Port 50000/UDP could cause a denial of service of the affected device. A manual reboot is required to return the device to service. CVE-2015-5374 [b] has been assigned to this vulnerability. A CVSS v2 base score of 7.8 has been assigned; the CVSS vector string is (AV:N/AC:L/Au:N/C:N/I:N/A:C). [c] VULNERABILITY DETAILS EXPLOITABILITY This vulnerability could be exploited remotely. EXISTENCE OF EXPLOIT No known public exploits specifically target this vulnerability. DIFFICULTY An attacker with a low skill would be able to exploit this vulnerability. MITIGATION Siemens has provided firmware update V4.25 for the EN100 module to fix the vulnerability. The firmware update for SIPROTEC 4 can be obtained here: http://www.siemens.com/downloads/siprotec-4 The firmware update for SIPROTEC Compact can be obtained here: http://www.siemens.com/downloads/siprotec-compact For more information on this vulnerability and more detailed mitigation instructions, please see Siemens Security Advisory SSA-732541 at the following location: http://www.siemens.com/cert/advisories ICS-CERT recommends that users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Specifically, users should: Configure firewall rules to appropriately restrict traffic to affected devices on Port 50000/UDP. Monitor traffic to affected devices on Port 50000/UDP with an intrusion detection system (IDS). 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 at: http://ics-cert.us-cert.gov/content/recommended-practices. 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 (http://ics-cert.us-cert.gov/). 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-400: Uncontrolled Resource Consumption ('Resource Exhaustion'), http://cwe.mitre.org/data/definitions/400.html, web site last accessed July 21, 2015. b. NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-5374, 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, http://nvd.nist.gov/cvss.cfm?version=2&vector=AV:N/AC:L/Au:N/C:N/I:N/A:C, web site last accessed July 21, 2015. Contact Information For any questions related to this report, please contact ICS-CERT at: Email: firstname.lastname@example.org 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 email@example.com 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: firstname.lastname@example.org 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 iQIVAwUBVa8i0n6ZAP0PgtI9AQKxPw//apBj7ObGQHvpv9Jk6dICdSePgSCvkXpp YxlNiBh8BNuBcg/GLlxFji8my5AWx5d3GjqVxoLkP0LYajfq8jruUs9wJpRd/r+T U670Dw31xCK7gFPBOyEEb7H10K+jfOAj0DdQVBA64RdwZ5Yfyi1ge5UkNZXGhhQh agTwmgCGFuY7IF3Q+9pFV2be92SEMAvjhVHDzuDjMXK09oHiBLLHqeFohrYF4+/u VzKz3pD7FmLzVPdy1hcz8fZYGmQu+SpqUX2mlMgvBs14oKMtnQdmkXdkAwviz6Je klkjDphp7G8XiHzFrGTq4M3YAZp7yrCGWDajrgAt3rQDxWCByKTo5VxK76sdzofY sxwAJ/mnS4kNt/HVQzFAQPLgvKmYwKP7Zedq3yFcBtZo/e1Hso7/EDUFVHiZde8D Uc+vbOaPL98LNaQy8vA+FWyMwvYGelQ36re+suFDsF6PSymCZl1BmStdEGEEZGeg gprkQZcFKI6D0uXOCBODmxDJjPXvLXzRS3fUzOn5IUw8SLJir4hW3YMWAxeHIVp5 zO83iR82Bi87oDWTxqLcjz0haVGeQyRl2dHFaIpXJjWQuNGTUfpCM45ulDgKjz97 FLdoS8OTEZt+TiRlTyjsHyxlKk+SqUrkcvsWmirBlSQDwucIrYmkM56CXLE1DE0d 9uifHCLM8gY= =i8ZR -----END PGP SIGNATURE-----