CVE-2025-11785 is a stack-based buffer overflow vulnerability identified in Circutor's SGE-PLC1000 and SGE-PLC50 devices, specifically in version 9.0.2 of their firmware/software. The vulnerability arises from the ShowMeterPasswords() function, which uses the unsafe sprintf() function to copy user-supplied input from the 'meter' parameter into a fixed-size buffer without validating the input length. The GetParameter(meter) function retrieves this input directly from the user, allowing an attacker to supply an excessively large string. Because sprintf() does not perform bounds checking, this leads to a classic stack buffer overflow (CWE-121), which can overwrite adjacent memory on the stack. Exploiting this flaw could allow an attacker to execute arbitrary code with the privileges of the affected process, cause a denial of service through crashes, or corrupt sensitive data. The CVSS 4.0 vector indicates the attack requires adjacent network access (AV:A), low attack complexity (AC:L), no attack prerequisites (AT:N), and low privileges (PR:L), with no user interaction (UI:N). The vulnerability impacts confidentiality, integrity, and availability at high levels, with a scope limited to the vulnerable component but potentially affecting the entire device operation. No patches are currently available, and no exploits have been observed in the wild. The vulnerability was reserved on 2025-10-15 and published on 2025-12-02 by INCIBE, the Spanish National Cybersecurity Institute, indicating credible recognition and reporting.

For European organizations, especially those in critical infrastructure sectors such as energy management, industrial automation, and utilities, this vulnerability poses a significant risk. Circutor's SGE-PLC1000 and SGE-PLC50 devices are used for power monitoring and control, making them integral to operational technology (OT) environments. Exploitation could lead to unauthorized control or disruption of power systems, causing outages or damage to equipment. Confidentiality breaches could expose sensitive operational data or credentials, while integrity violations could manipulate measurement data, leading to incorrect operational decisions. Availability impacts could result in denial of service, halting critical processes. The requirement for only low privileges and no user interaction increases the likelihood of exploitation in environments where these devices are network accessible. The absence of known exploits currently provides a window for mitigation, but the high CVSS score underscores the urgency. European organizations relying on these devices must consider the potential for targeted attacks, especially given geopolitical tensions affecting energy infrastructure security.

1. Immediately restrict network access to Circutor SGE-PLC1000 and SGE-PLC50 devices to trusted management networks only, using network segmentation and firewall rules. 2. Monitor network traffic for anomalous or unexpected requests targeting the 'meter' parameter or related device interfaces. 3. Implement strict input validation and filtering at network gateways or proxies to block oversized or malformed inputs directed at these devices. 4. Coordinate with Circutor for timely release and deployment of security patches or firmware updates addressing this vulnerability. 5. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics tuned to detect exploitation attempts of buffer overflow patterns. 6. Conduct regular security audits and vulnerability assessments of OT environments to identify and remediate similar unsafe coding practices. 7. Train operational technology personnel on secure configuration and incident response specific to these devices. 8. Maintain up-to-date asset inventories to quickly identify affected devices and prioritize remediation efforts.