| Title | Tenda AC21 V16.03.08.16 Buffer Overflow |
|---|
| Description | During a security review of the application, a critical stack-based buffer overflow vulnerability was discovered in the “/goform/AdvSetMacMtuWan” endpoint. The vulnerability is triggered within the `fromAdvSetMacMtuWan` function and its internal helper function `sub_44C7A8`.
In this workflow, the parent function allocates a stack buffer and passes its address to the helper function `sub_44C7A8`. Inside the helper function, the `websGetVar` function is used to retrieve user-supplied parameters such as `serverName`, `serviceName`, and `wanMTU` from the incoming POST request. The application then uses the unsafe `strcpy` function to copy these parameters directly into the stack buffer provided by the parent function.
Due to the lack of proper bounds checking on the input length, a malicious actor can supply an oversized `serverName` (or `wanMTU`) parameter. This action overflows the destination buffer, overwriting the program's stack frames, including the return address. This can lead to application crashes (Denial of Service), memory corruption, and potentially allow for arbitrary code execution on the server. Immediate remediation is required to mitigate this high-impact risk. |
|---|
| Source | ⚠️ https://github.com/LX-LX88/cve/issues/25 |
|---|
| User | LX-LX (UID 91683) |
|---|
| Submission | 01/16/2026 17:07 (5 months ago) |
|---|
| Moderation | 01/29/2026 17:56 (13 days later) |
|---|
| Status | Accepted |
|---|
| VulDB entry | 343416 [Tenda AC21 16.03.08.16 /goform/AdvSetMacMtuWan fromAdvSetMacMtuWan stack-based overflow] |
|---|
| Points | 20 |
|---|