A stack-based buffer overflow exists in the start_httpd function of the Trendnet TEW‑635BRM router’s web service. The flaw is triggered by manipulating the device_name argument passed to the /sbin/rc script, which the router executes when handling web requests. Because the overflow corrupts the stack, an attacker who can send crafted requests to the device over the network can achieve arbitrary code execution, effectively compromising the router. The vulnerability maps to CWE‑119 and CWE‑121, indicating unsafe buffer handling and stack corruption.

Trendnet TEW‑635BRM routers with firmware versions up to 1.00.03 are affected. The device is end‑of‑life since 2011, and no security patch is available from the manufacturer.

The CVSS score is 8.7, classifying the issue as high severity. The EPSS score is less than 1 %, pointing to a low current exploitation probability, but a publicly available exploit exists and the device’s unsupported status makes it a likely target. Based on the description, the likely attack vector is remote via the device’s web interface, although the exact interface is not specified. The vulnerability is not listed in the CISA KEV catalog.