CVE-2026-62653 in Reyrolle 7SR5
Summary
by MITRE • 09/08/2026
A vulnerability has been identified in Reyrolle 7SR5 (All versions < V2.70). The input received over a proprietary communication protocol that is exposed when the device is placed into a special firmware-update mode is not properly validated, resulting in a memory corruption condition. This could allow an unauthenticated attacker with physical access to the device to cause a crash and potentially execute arbitrary code on the device.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 09/08/2026
The Reyrolle 7SR5 series of protection relays represents critical infrastructure within modern electrical power grids, serving as essential components for monitoring, protecting, and controlling high-voltage networks. These devices are engineered to withstand harsh industrial environments and operate with a high degree of reliability over extended periods. However, the identified vulnerability in firmware versions prior to V2.70 exposes a significant security gap related to physical access controls and input validation mechanisms during maintenance operations. The core issue stems from how the device handles data inputs when it is placed into a special firmware-update mode. This specific operational state is designed for authorized personnel to update or restore the device's software, but it inadvertently creates an attack surface that lacks adequate security boundaries compared to normal operating modes.
The technical flaw lies in the insufficient validation of input received over a proprietary communication protocol while the device is in this maintenance state. When an attacker gains physical access to the relay and can trigger or exploit the firmware-update mode, they are able to send malformed data packets through the exposed interface. Because the system fails to properly validate these inputs before processing them, it leads directly to memory corruption conditions within the device's internal buffers. This type of flaw is characteristic of buffer overflow vulnerabilities where input data exceeds the allocated memory space or contains maliciously crafted structures that overwrite adjacent memory locations. The lack of rigorous boundary checks allows an unauthenticated attacker to manipulate the program counter or other critical control flow elements stored in memory, thereby disrupting normal execution paths.
The operational impact of this vulnerability is severe due to its potential for both denial of service and arbitrary code execution. An unauthenticated attacker with physical access can exploit the memory corruption to crash the device, resulting in a complete loss of protection functionality for the associated electrical circuit. In power systems, such a failure could lead to cascading outages or equipment damage if protective tripping mechanisms fail during fault conditions. More critically, the ability to execute arbitrary code on the device poses an existential threat to grid integrity. An attacker with control over the relay's firmware could potentially alter protection settings, delay trip commands, or inject false data into supervisory control and data acquisition systems connected to the network. This transforms a simple hardware maintenance interface into a vector for sophisticated cyber-physical attacks against critical energy infrastructure.
This vulnerability aligns closely with Common Weakness Enumeration identifier CWE-120, which describes buffer copy without checking size limits, as well as CWE-787, concerning out-of-bounds write access. From an offensive security perspective, the exploitation path corresponds to MITRE ATT&CK techniques involving physical interaction and local privilege escalation or code execution via memory corruption. The reliance on a proprietary protocol does not inherently provide security through obscurity if the implementation fails at fundamental input validation stages during privileged operational modes.
Mitigation strategies must prioritize both immediate patching and long-term architectural improvements. For existing installations, it is imperative to upgrade all Reyrolle 7SR5 devices to version V2.70 or later, where this specific input validation flaw has been addressed by the manufacturer. Until patches are applied, physical access controls should be strictly enforced, ensuring that only authorized personnel with appropriate credentials can place devices into firmware-update modes. Additionally, network segmentation strategies should isolate protection relays from general corporate networks to limit lateral movement in case of a breach. Future procurement and design processes must mandate rigorous security testing for all maintenance interfaces, ensuring that even privileged operational states enforce strict input sanitization and memory safety checks consistent with secure coding standards such as those outlined by the OWASP or IEC 62443 series for industrial automation and control systems security.