CVE-2025-11786 is a stack-based buffer overflow vulnerability identified in Circutor's SGE-PLC1000 and SGE-PLC50 devices, specifically in version 9.0.2. The vulnerability arises from insecure coding in the SetUserPassword() function, where the 'newPassword' parameter is directly embedded into a shell command string using sprintf() without any sanitization or validation. This string is then executed via the system() call, which executes shell commands with the same privileges as the application. Because the input is not validated, an attacker can inject arbitrary shell commands, leading to command injection and potential full system compromise. The vulnerability requires low attack complexity, no user interaction, and only low privileges to exploit, but it impacts confidentiality, integrity, and availability highly due to the ability to execute arbitrary commands. The CVSS 4.0 vector indicates the attack is remote (AV:A - adjacent network), requires low privileges (PR:L), no user interaction (UI:N), and has high impact on confidentiality, integrity, and availability. No patches or known exploits are currently available, but the vulnerability is publicly disclosed and assigned a high severity rating. The flaw is categorized under CWE-121 (stack-based buffer overflow), indicating that the buffer overflow can overwrite the stack, potentially allowing control over the execution flow. Given the nature of the affected devices—programmable logic controllers used in industrial environments—successful exploitation could lead to disruption or manipulation of critical infrastructure processes.

The impact of CVE-2025-11786 on European organizations is significant, particularly for those operating industrial control systems (ICS) or critical infrastructure that utilize Circutor SGE-PLC1000 and SGE-PLC50 devices. Exploitation can lead to arbitrary command execution with the privileges of the vulnerable application, potentially allowing attackers to disrupt industrial processes, manipulate operational data, or cause denial of service. This threatens the confidentiality, integrity, and availability of critical systems, potentially leading to operational downtime, safety hazards, and financial losses. Since the attack vector is from an adjacent network, organizations with segmented but accessible industrial networks are at risk. The lack of authentication requirements and user interaction lowers the barrier for exploitation once network access is obtained. European energy providers, manufacturing plants, water treatment facilities, and transportation systems using these devices could face targeted attacks aiming to disrupt services or cause physical damage. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as public disclosure may prompt adversaries to develop exploits. The high CVSS score reflects the potential for severe operational impact and data compromise.

1. Immediately implement strict network segmentation to isolate Circutor SGE-PLC devices from general enterprise networks and restrict access to trusted hosts only. 2. Enforce strong access control policies, including multi-factor authentication and role-based access, to limit who can interact with the vulnerable devices. 3. Monitor network traffic and device logs for unusual command execution patterns or unauthorized access attempts, using IDS/IPS tuned for ICS environments. 4. Disable or restrict remote management interfaces if not strictly necessary, or secure them with VPNs and strong authentication. 5. Until a vendor patch is released, avoid using the SetUserPassword() function remotely or restrict its usage to trusted administrators. 6. Engage with Circutor for timely updates and patches; prioritize patch deployment once available. 7. Conduct regular security audits and penetration tests focusing on industrial control systems to identify and remediate similar vulnerabilities. 8. Train operational technology (OT) staff on recognizing signs of exploitation and incident response procedures specific to ICS environments. 9. Maintain up-to-date asset inventories to quickly identify affected devices and assess exposure. 10. Consider deploying application whitelisting or endpoint protection solutions tailored for ICS to prevent unauthorized command execution.