Mitsubishi Electric Corporation has identified a denial-of-service (DoS) vulnerability in its MELSEC iQ-R, Q, and L series CPU modules, affecting their Ethernet communication. This vulnerability arises from uncontrolled resource consumption, which occurs when the CPU module receives a specially crafted packet from a malicious attacker. This can cause the Ethernet communication to enter a DoS condition, requiring a reset to recover the system. The affected models span across multiple series, including iQ-R, Q, and L series, with several firmware and operating system versions vulnerable to this issue. The vulnerability is tracked as CVE-2020-5652 and has a CVSS base score of 7.5.
The affected product models include various MELSEC iQ-R, Q, and L series CPU modules, with specific firmware and operating system versions outlined in the advisory. For example, iQ-R series modules with firmware versions “20” or earlier and Q series models with serial numbers “22081” or earlier are vulnerable. The advisory provides a comprehensive list of affected models, serial numbers, and firmware versions to help customers determine if their devices are at risk. Mitsubishi Electric has made available instructions for customers to check their device’s firmware and operating system versions, which can be found on their official website.
To address this issue, Mitsubishi Electric recommends updating the affected products to the fixed versions. For some modules, an update is available to resolve the vulnerability, while others may not have an update option due to hardware limitations. The fixed versions for the vulnerable models are detailed in the advisory. For devices that cannot be updated, Mitsubishi Electric suggests mitigation measures, such as using firewalls or virtual private networks (VPNs) to prevent unauthorized access or restricting access to trusted networks only.
In response to the vulnerability, Mitsubishi Electric expressed gratitude to the individual who reported the issue. They have also updated the advisory several times, including adding new details about affected product models, firmware versions, and operating system versions. As of the latest update in September 2024, the advisory includes instructions on checking for updates, upgrading firmware, and the necessary mitigations for unupdatable devices. Customers are encouraged to consult their local Mitsubishi Electric representatives for further assistance.
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