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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2018.2706 Advisory (ICSA-18-254-05) 12 September 2018 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Siemens SCALANCE X Switches Publisher: ICS-CERT Operating System: Network Appliance Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2018-13807 Original Bulletin: https://ics-cert.us-cert.gov/advisories/ICSA-18-254-05 - --------------------------BEGIN INCLUDED TEXT-------------------- Advisory (ICSA-18-254-05) Siemens SCALANCE X Switches Original release date: September 11, 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 8.6 o ATTENTION: Exploitable remotely/low skill level to exploit/public exploits are available o Vendor: Siemens o Equipment: SCALANCE X Switches o Vulnerability: Improper Input Validation 2. RISK EVALUATION Successful exploitation of this vulnerability could allow an attacker with network access to the device to cause a denial-of-service condition. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS The following versions of SCALANCE X Switches, which are used to connect industrial components like programmable logic controllers (PLCs) or human machine interfaces (HMIs), are affected: o SCALANCE X300: All versions prior to 4.0.0, o SCALANCE X408: All versions prior to 4.0.0 and o SCALANCE X414: All versions. 3.2 VULNERABILITY OVERVIEW 3.2.1 IMPROPER INPUT VALIDATION CWE- 20 The web interface on Port 443/TCP could allow an attacker to cause a denial-of-service condition by sending specially crafted packets to the web server. The device will automatically reboot, impacting network availability for other devices. An attacker must have network access to Port 443/TCP to exploit the vulnerability. Neither valid credentials nor interaction by a legitimate user are required to exploit the vulnerability. There is no confidentiality or integrity impact, availability is only temporarily impacted. This vulnerability could be exploited by publicly available tools. CVE-2018-13807 has been assigned to this vulnerability. A CVSS v3 base score of 8.6 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H). 3.3 BACKGROUND o CRITICAL INFRASTRUCTURE SECTORS: Chemical, Energy, Food and Agriculture, and Water and Wastewater Systems o COUNTRIES/AREAS DEPLOYED: Worldwide o COMPANY HEADQUARTERS LOCATION: Germany 3.4 RESEARCHER Siemens reported this vulnerability to NCCIC. 4. MITIGATIONS Siemens provides updates for SCALANCE X300, and SCALANCE X408, and provides mitigations for the SCALANCE X414. o SCALANCE X300: Update to Version 4.1.2 https://support.industry.siemens.com/cs/us/en/view/109753720 o SCALANCE X408: Update to Version 4.1.2 https://support.industry.siemens.com/cs/us/en/view/109753720 o SCALANCE X424: Siemens has identified the following specific workarounds and mitigations that users can apply to reduce the risk: o Protect network access to the integrated web server on Port 443/TCP with appropriate mechanisms. o Restrict network access to Port 443/TCP to trusted IP addresses, and avoid running vulnerability scanning tools from trusted IP addresses on affected devices. As a general security measure, Siemens strongly recommends to protect network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends to configure the environment according to Siemens' operational guidelines for Industrial Security (download: https://www.siemens.com/cert/operational-guidelines-industrial-security), and to follow 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-447396 on their web site: 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. Contact Information For any questions related to this report, please contact the NCCIC at: Email: NCCICCUSTOMERSERVICE@hq.dhs.gov Toll Free: 1-888-282-0870 For industrial control systems cybersecurity information: http://ics-cert.us-cert.gov or incident reporting: https://ics-cert.us-cert.gov/Report-Incident? The NCCIC 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: 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 iQIVAwUBW5hh5maOgq3Tt24GAQgd7g/+LNvcDyXBqg2TiK7CiwFJPDxVUwJQH+12 KxDIJr0XJ3BeejYgK1cHWQIAZ6Bhr26/xU1zwMBdsbE/hyLkozmbLhkgMJFxTC6j 896M5eNO4gA47yk3IC0YC9GO6zlytiAmXDE6ZJdXyC/TAIJ73g2syQ8XqatE1sFv P3ynpx+5BYzbGFGYOlMzg/qtj87X6GSgusQUj0oC3mQ0cszVSD6cYy/UukY/vSh3 Kf/o/pRiToR5gEPqkB5bdvS8hb8zU+A+Kx4QdKW1bBaKPbGjscQ/VTKJOk0x4NOB DUMB7LDW0tCHxgWntSxZv51v1pBJFAh/Go+A1YivU+Jy5Ml0UV2Q4H9rQ6BnWwue OKr0+//qM+6qTYXeRtB9BN5yWELSlnuQf2wgrTO9Ej5WjaEufckJoq8EE88quKeX qeggH2tQp/9V1LwWziUuW2lTn6MNzMY5HREF29OmTz7jCktf9a15f3YQS0qTQnC1 OeeRCcsiumJWMgOaqd9zBQmaEuquVALEZS16Aw/eUxu7Q8h0+9H2qr0O+SzxUqEj sb9RfAh1xKa8jkHr4BsaTwBuCawft8OMglitRWUJIKoTI3Mb8tjGOO/hpRsgze/w ANg0kSpf0EqXG9ieyi9JA/xae4EDgAqoFnUiHSMa7rsH4OBmws6Xi+6M9NieYNRQ lhrQYWPmWDM= =fuzz -----END PGP SIGNATURE-----