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1. EXECUTIVE SUMMARY
- CVSS v3 7.5
- ATTENTION: Exploitable remotely/low skill level to exploit
- Vendor: Mitsubishi Electric
- Equipment: MELSEC-Q series Ethernet module
- Vulnerability: Uncontrolled Resource Consumption
2. RISK EVALUATION
Successful exploitation of this vulnerability may render the device unresponsive, requiring a physical reset of the PLC (Programmable Logic Controller).
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
The following MELSEC-Q series Ethernet module is affected:
- QJ71E71-100 serial number 20121 and prior
3.2 VULNERABILITY OVERVIEW
An attacker could send crafted TCP packets against the FTP service, forcing the target devices to enter an error mode and cause a denial-of-service condition.
- CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing
- COUNTRIES/AREAS DEPLOYED: Worldwide
- COMPANY HEADQUARTERS LOCATION: Japan
Younes Dragoni and Alessandro Di Pinto of Nozomi Networks reported this vulnerability to Mitsubishi and NCCIC.
Mitsubishi Electric has released new firmware Version 20122 for the QJ71E71-100 Ethernet module to mitigate the reported vulnerability.
Additional information about the vulnerabilities or Mitsubishi Electric's compensating control is available by contacting a local Mitsubishi Electric representative, which can be found at the following location:
Mitsubishi Electric strongly recommends that users should operate the affected device behind a firewall.
NCCIC recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:
- 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.
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.
For any questions related to this report, please contact the CISA at:
Toll Free: 1-888-282-0870
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