CVE-2025-15080 is a vulnerability classified under CWE-1284 (Improper Validation of Specified Quantity in Input) affecting Mitsubishi Electric Corporation's MELSEC iQ-R Series programmable logic controllers (PLCs), specifically models R08PCPU, R16PCPU, R32PCPU, and R120PCPU running firmware version 48 or earlier. The flaw arises because the affected devices do not properly validate the quantity parameter in input commands. This improper validation enables an unauthenticated attacker to send specially crafted packets containing specific commands that can manipulate the device's internal data. Exploitation allows attackers to read sensitive device data or portions of the control program, write or modify device data, or cause a denial of service (DoS) condition by disrupting normal device operation. The vulnerability is remotely exploitable over the network without requiring any authentication or user interaction, increasing its risk profile. The CVSS 4.0 base score is 8.8 (high), reflecting the ease of exploitation and the significant impact on confidentiality, integrity, and availability. This vulnerability threatens the operational stability and security of industrial control systems that rely on these PLCs, potentially leading to unauthorized control, data leakage, or process disruption. No known exploits are currently reported in the wild, but the lack of patches at the time of reporting emphasizes the need for proactive mitigation. The vulnerability's root cause is a failure in input validation logic, which is a common and critical security oversight in embedded and industrial devices. Given the critical infrastructure role of these PLCs, exploitation could have severe consequences in industrial environments.

For European organizations, the impact of CVE-2025-15080 is substantial, especially those operating in manufacturing, energy production, utilities, transportation, and critical infrastructure sectors where Mitsubishi MELSEC iQ-R Series PLCs are deployed. Successful exploitation can lead to unauthorized disclosure of sensitive control program data, enabling industrial espionage or intellectual property theft. Integrity of control processes can be compromised by unauthorized modification of device data, potentially causing unsafe operating conditions, production errors, or equipment damage. Denial of service attacks could halt industrial operations, leading to financial losses, safety hazards, and disruption of supply chains. The lack of authentication and remote exploitability increases the attack surface, making these PLCs attractive targets for cybercriminals or state-sponsored actors aiming to disrupt European industrial operations. The potential cascading effects on interconnected systems and the critical nature of affected sectors amplify the threat's severity. Additionally, regulatory compliance risks arise if organizations fail to adequately protect these systems, potentially resulting in penalties under frameworks like NIS2 or GDPR if personal or operational data is compromised.

1. Immediate network segmentation: Isolate MELSEC iQ-R Series PLCs from general IT networks and restrict access to trusted management stations only. 2. Implement strict firewall rules and access control lists (ACLs) to block unauthorized traffic to PLC communication ports, allowing only known and necessary protocols. 3. Monitor network traffic for anomalous packets or commands targeting the PLCs, employing intrusion detection systems (IDS) tailored for industrial protocols. 4. Apply vendor firmware updates as soon as Mitsubishi Electric releases patches addressing CVE-2025-15080; maintain a patch management process for industrial devices. 5. Employ strong physical security controls to prevent unauthorized local access to PLCs. 6. Conduct regular security audits and vulnerability assessments of industrial control systems to identify and remediate similar input validation issues. 7. Train operational technology (OT) personnel on recognizing and responding to potential exploitation attempts. 8. Where possible, implement application-layer gateways or protocol proxies that validate and sanitize commands sent to PLCs to prevent malformed inputs. 9. Maintain up-to-date asset inventories to quickly identify affected devices and prioritize remediation efforts. 10. Collaborate with Mitsubishi Electric and industrial cybersecurity communities to stay informed about emerging threats and mitigation techniques.