CVE-2025-11779 is a stack-based buffer overflow vulnerability classified under CWE-121, affecting Circutor's SGE-PLC1000 and SGE-PLC50 devices running firmware version 9.0.2. The vulnerability arises in the 'SetLan' function, which is invoked when new configurations are applied via the device's management web interface, specifically through the 'index.cgi' application. The root cause is the lack of input sanitization on parameters passed during configuration changes, enabling an attacker to perform command injection. This flaw allows an attacker with low privileges (PR:L) and no user interaction (UI:N) to execute arbitrary code remotely over an adjacent network (AV:A). The vulnerability impacts confidentiality, integrity, and availability at a high level (VC:H, VI:H, VA:H), indicating potential full system compromise, data leakage, or denial of service. The CVSS 4.0 score of 9.4 underscores the criticality of this issue. Although no public exploits have been reported yet, the vulnerability's characteristics make exploitation feasible, especially in environments where management interfaces are exposed or insufficiently protected. The affected devices are commonly used in industrial and energy management contexts, where reliability and security are paramount. The vulnerability was reserved on 2025-10-15 and published on 2025-12-02 by INCIBE, highlighting its recent discovery and the need for immediate attention.

For European organizations, this vulnerability poses a significant threat, particularly to those operating critical infrastructure such as energy distribution, industrial automation, and building management systems where Circutor devices are deployed. Exploitation could lead to unauthorized command execution, allowing attackers to disrupt operations, manipulate device configurations, or cause denial of service. This can result in operational downtime, safety hazards, financial losses, and potential regulatory penalties under frameworks like NIS2 and GDPR if sensitive data or critical services are impacted. The vulnerability's ability to be exploited remotely with low privileges and no user interaction increases the attack surface, especially if management interfaces are accessible from internal or external networks. Given the strategic importance of energy and industrial sectors in Europe, successful exploitation could have cascading effects on supply chains and public services.

1. Immediately restrict network access to the management web interface of affected Circutor devices, ideally isolating them on dedicated management VLANs or networks with strict firewall rules. 2. Implement strong authentication and access control measures to limit who can apply configuration changes. 3. Employ web application firewalls (WAFs) or intrusion prevention systems (IPS) to detect and block malicious payloads targeting the 'index.cgi' endpoint. 4. Monitor device logs and network traffic for unusual configuration changes or command execution attempts. 5. Coordinate with Circutor for firmware updates or patches addressing CVE-2025-11779 and apply them promptly once available. 6. If patches are not yet available, consider temporary mitigations such as disabling remote configuration capabilities or limiting configuration changes to trusted administrators via secure channels. 7. Conduct regular security assessments and penetration tests on industrial control systems to identify and remediate similar vulnerabilities proactively.