The sub_41EC14 function in the /goform/tools_nslookup endpoint on TRENDnet TEW-821DAP routers contains a memory buffer overflow, identified as CWE-119 and CWE-120. When the endpoint receives specially crafted data, the overflow can corrupt memory, potentially leading to device compromise. The vendor has not released a fix because the affected firmware is end-of-life, and the security advisory does not confirm whether arbitrary code execution is possible, but the nature of the overflow suggests that such a capability could be achievable. The vulnerability can be triggered remotely via standard HTTP requests to the exposed endpoint.

TRENDnet TEW-821DAP routers running firmware 1.12B01 are affected; these models are no longer maintained or supported by the vendor, who has declared them end-of-life and indicated that no patches will be provided. It is unclear whether firmware versions older than 1.12B01 are vulnerable; no explicit statement is available.

The CVSS score of 8.7 classifies it as a high‑severity flaw, while an EPSS score of <1% indicates a presently low likelihood of exploitation. It is not listed in the CISA KEV catalog. Because the attack vector is remote and the flaw resides in publicly accessible web code, an attacker only needs to send crafted HTTP requests over the network. The absence of a vendor patch and the end‑of‑life status increase the risk, as unpatched devices remain vulnerable.