ATTENTION: Remotely exploitable/low skill level to exploit.
Equipment: Industrial products
Vulnerability: Improper Input Validation
This updated advisory is a follow-up to the updated advisory titled ICSA-17-339-01B Siemens Industrial Products that was published January 23, 2018, on the NCCIC/ICS-CERT web site.
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Siemens reports the vulnerability affects the following industrial products:
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Successful exploitation of this vulnerability may allow a remote attacker to conduct a denial-of-service (DoS) attack.
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Siemens has provided firmware updates for the following products to fix the vulnerability:
Please contact a Siemens representative for information on how to obtain the update.
For ET 200MP PN BA: Update to V4.0.2. For all ET 200MP devices: Follow recommendations from section Workaround and Mitigations.
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Siemens is preparing further updates and recommends the following mitigations until patches are available:
Siemens recommends users configure the operational environment according to Siemens’ Operational Guidelines for Industrial Security:
For more information on the vulnerability and more detailed mitigation instructions, please see Siemens Security Advisory SSA-346262 at the following location:
NCCIC recommends that users take defensive measures to minimize the risk of exploitation of this vulnerability. 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 in the NCCIC 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 NCCIC for tracking and correlation against other incidents.
No known public exploits specifically target this vulnerability.
Specially crafted packets sent to Port 161/UDP could cause a denial-of-service condition. The affected devices must be restarted manually.
George Lashenko of CyberX reported the vulnerability to Siemens.
Critical Infrastructure Sectors: Commercial Facilities, Critical Manufacturing, Energy, Food and Agriculture, Water and Wastewater Systems
Countries/Areas Deployed: Worldwide
Company Headquarters Location: Germany