CVE-2025-3511 is a vulnerability classified under CWE-1284 (Improper Validation of Specified Quantity in Input) found in Mitsubishi Electric Corporation's CC-Link IE TSN series of industrial automation modules. The affected products include Remote I/O modules (NZ2GN2S1-32D), Analog-Digital and Digital-Analog Converter modules, FPGA modules, communication LSIs (CP620 and CP610), and various MELSEC iQ-R and iQ-F Series Master/Local and Ethernet interface modules. The vulnerability arises because these devices do not properly validate the quantity field in incoming UDP packets, allowing an attacker to send specially crafted packets that trigger a Denial of Service (DoS) condition. The attack vector is network-based, requiring no authentication or user interaction, which increases the risk of exploitation. The CVSS v3.1 base score is 7.5 (high), reflecting the network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no impact on confidentiality or integrity (C:N/I:N), but high impact on availability (A:H). This vulnerability can cause affected devices to become unresponsive or crash, disrupting industrial processes controlled by these modules. No patches were listed at the time of disclosure, and no known exploits have been reported in the wild. The vulnerability affects firmware versions 09 and prior. Given the critical role of these modules in industrial control systems (ICS) and manufacturing environments, exploitation could lead to operational downtime and safety risks.

For European organizations, the impact of CVE-2025-3511 is significant due to the widespread use of Mitsubishi Electric CC-Link IE TSN modules in industrial automation, manufacturing, energy production, and critical infrastructure sectors. A successful DoS attack can halt production lines, disrupt energy distribution, or impair safety monitoring systems, leading to financial losses, safety hazards, and potential regulatory non-compliance. The lack of required authentication and the network-based attack vector mean that attackers can exploit this vulnerability remotely, potentially from outside the organization’s perimeter if network segmentation is insufficient. This increases the risk of supply chain disruptions and operational downtime. Additionally, the unavailability of these modules could impact critical infrastructure resilience, which is a priority for European cybersecurity frameworks. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as attackers often develop exploits following public disclosure. The impact is exacerbated in environments where redundancy or failover mechanisms are limited or where patching is delayed due to operational constraints.

1. Apply patches or firmware updates from Mitsubishi Electric as soon as they become available to address this vulnerability. 2. Implement strict network segmentation to isolate CC-Link IE TSN devices from general IT networks and untrusted external networks. 3. Deploy network-level filtering and intrusion detection/prevention systems (IDS/IPS) to monitor and block suspicious UDP traffic targeting the affected modules, especially filtering unexpected or malformed packets. 4. Restrict access to management interfaces and control networks to authorized personnel and trusted devices only, using strong access controls and network authentication mechanisms. 5. Conduct regular vulnerability assessments and penetration testing focused on industrial control systems to identify and remediate exposure. 6. Develop and test incident response plans specific to industrial control system disruptions to minimize downtime in case of exploitation. 7. Maintain up-to-date asset inventories to quickly identify affected devices and prioritize remediation efforts. 8. Collaborate with Mitsubishi Electric support and industrial cybersecurity communities to stay informed about patches, advisories, and emerging threats related to CC-Link IE TSN products.