CVE-2026-10121

Vulnerability

A stack-based buffer overflow vulnerability exists in the formSetUrlFilter function of the boa binary on TRENDnet TEW-432BRP routers running firmware version 3.10B20. The function directly copies user-supplied data from the keyword_list and keyword parameters into a fixed-size stack buffer without proper bounds checking, leading to a buffer overflow. The vulnerable code path is reachable via the /goform/formSetUrlFilter endpoint [1].

Exploitation

An unauthenticated attacker can exploit this vulnerability remotely by sending a crafted HTTP POST request to the /goform/formSetUrlFilter endpoint with an overly long keyword_list parameter. The PoC demonstrates that sending a string of approximately 877 'a' characters triggers a crash, indicating memory corruption. By carefully controlling the overflow, an attacker can overwrite the return address and achieve arbitrary code execution [1].

Impact

Successful exploitation allows an attacker to execute arbitrary code on the affected device with root privileges, leading to full compromise of the router. This could result in denial of service, information disclosure, or further network attacks [1].

Mitigation

The vendor has stated that the TRENDnet TEW-432BRP model has been end-of-life since 2009 and no patches or updates will be provided. Users are strongly advised to replace the device with a supported alternative to mitigate the risk. No workaround exists [1].