OpenPLI OS Command Execution / Cross Site Scripting

[Praetorian503]

OpenPLI Dream Multimedia Box suffers from cross site scripting and remote OS command injection vulnerabilities.

Device Name: OpenPLI - Dream Multimedia Box with OpenPLI software
Vendor of device: Dream Multimedia
Vendor of Software: OpenPLI Community

============ Device Details: ============ 

Linux Kernel  Linux version 2.6.9 (build@plibouwserver) (gcc version 3.4.4) #1 Wed Aug 17 23:54:07 CEST 2011
Firmware  release 1.1.0, 27.01.2013
FP Firmware  1.06
Web Interface  6.0.4-Expert - PLi edition by [lite]

More infos: http://openpli.org/

============ Vulnerability Overview: ============ 

* OS Command Execution:

  parameter: maxmtu

The vulnerability is caused by missing input validation in the maxmtu parameter and can be exploited to inject and execute arbitrary shell commands. It is possible to use Netcat to fully compromise the device.

http://Target-IP/cgi-bin/setConfigSettings?maxmtu=%26COMMAND%26&hddstandby=2&hddacoustics=160&timeroffsetstart=0&timeroffsetstop=0&audiochannelspriority=&showsatpos=on&trustedhosts=&epgcachepath=%2Fhdd&epgsqlpath=%2Fvar%2Flib%2Fsqlite

It is possible to shorten the URL to the following:

http://Target-IP/cgi-bin/setConfigSettings?maxmtu=%26COMMAND%26

There is Netcat preinstalled on the device. It is a very small edition of netcat, so you have to play a bit with it but you will get it 

* stored XSS:

Box Control -> Configuration -> Webserver -> User, Password

  parameter: AuthUser, AuthPassword

Box Control -> Configuration -> Settings

  parameter: audiochannelspriority

Injecting scripts into the parameter audiochannelspriority reveals that this parameter is not properly validated for malicious input.

============ Solution ============

No known solution available.

============ Credits ============

The vulnerability was discovered by Michael Messner
Mail: devnull#at#s3cur1ty#dot#de
Web: http://www.s3cur1ty.de/advisories
Twitter: @s3cur1ty_de

Source: PacketStorm