ATTENTION: Remotely exploitable/low-skill level to exploit
Vendor: Schneider Electric
Equipment: Modicon M340 PLC
Vulnerability: Resource Exhaustion
Schneider Electric reports that the vulnerability affects the following Modicon PLC products with firmware versions prior to Version 2.9:
Successful exploitation of this vulnerability may render the device unresponsive requiring a physical reset of the PLC.
Schneider Electric has released a new firmware version, Version 2.9, to mitigate the identified vulnerability, which is available at the following location:
Schneider Electric recommends that users upgrade to the latest firmware version.
NCCIC/ICS-CERT recommends that users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:
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 ICS‑CERT 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. This vulnerability is not remotely exploitable.
A remote attacker could send a specially crafted set of packets to the PLC causing it to freeze, requiring the operator to physically press the reset button on the PLC in order to recover.
Luis Francisco Martin Liras reported the issue to Schneider Electric.
Critical Infrastructure Sector(s): Defense Industrial Base; Energy; Government Facilities; Nuclear Reactors, Materials, and Waste; Transportation Systems; Water and Wastewater Systems
Countries/Areas Deployed: United States, China, Russia, and India.
Company Headquarters Location: Paris, France