CVE-2025-11789 is an out-of-bounds read vulnerability identified in Circutor's SGE-PLC1000 and SGE-PLC50 devices, specifically in version 9.0.2 of their firmware/software. The vulnerability exists in the 'DownloadFile' function, which accepts a parameter that is converted to an integer using the standard C library function 'atoi()'. This integer is then used as an index to access the 'FilesDownload' array via the expression '(&FilesDownload)[iVar2]'. Due to the lack of proper bounds checking on this index, if an attacker supplies a value larger than the array's size, the function will read memory beyond the allocated array boundaries. This out-of-bounds read can lead to disclosure of sensitive information stored in adjacent memory regions, potentially leaking critical data or internal state information. The vulnerability is remotely exploitable without requiring authentication or user interaction, increasing the attack surface. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:L), no user interaction (UI:N), and high impact on confidentiality (VC:H) with no impact on integrity or availability. Although no public exploits are known, the vulnerability poses a significant risk due to the nature of the affected devices, which are used in industrial and energy management environments. The lack of patch availability at the time of disclosure necessitates immediate mitigation through compensating controls.

The primary impact of CVE-2025-11789 is the potential unauthorized disclosure of sensitive information from the memory of Circutor SGE-PLC1000 and SGE-PLC50 devices. For European organizations, especially those in critical infrastructure sectors such as energy distribution, industrial automation, and building management, this could lead to exposure of operational data, configuration details, or cryptographic material. Such information leakage could facilitate further targeted attacks, including sabotage, espionage, or disruption of services. Given that these devices often operate in supervisory control and data acquisition (SCADA) environments, the confidentiality breach could undermine trust in system integrity and complicate incident response. The vulnerability does not directly affect system integrity or availability but could be a stepping stone for more severe attacks. The ease of remote exploitation without authentication increases the risk profile, particularly for organizations with insufficient network segmentation or exposed management interfaces. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits post-disclosure.

1. Monitor Circutor's official channels for firmware updates or patches addressing CVE-2025-11789 and apply them promptly upon release. 2. Implement strict input validation and filtering at network boundaries to prevent malformed or unexpected requests targeting the 'DownloadFile' function. 3. Restrict network access to SGE-PLC1000 and SGE-PLC50 devices by enforcing network segmentation and firewall rules, limiting exposure to trusted management networks only. 4. Employ intrusion detection and prevention systems (IDS/IPS) with signatures or anomaly detection capabilities tailored to identify suspicious access patterns to the vulnerable function. 5. Conduct regular security audits and penetration tests focusing on industrial control systems to identify and remediate similar vulnerabilities. 6. Develop and rehearse incident response plans specific to industrial device compromises to minimize impact if exploitation occurs. 7. Where possible, disable or restrict unused services and interfaces on the affected devices to reduce attack surface. 8. Maintain detailed logging and monitoring of device access to facilitate forensic analysis in case of an incident.