D-Link UPnP M-Search Command Injection

This is the Metasploit module for the command injection detected and exploited by Zachary Cutlip:
http://shadow-file.blogspot.de/2013/02/dlink-dir-815-upnp-command-injection.html
https://github.com/zcutlip/exploit-poc/tree/master/dlink/dir-815-a1/upnp-command-injection

Tested on my DIR-300, DIR-645. Zach has reported the DIR-815 and there are a ton of devices with the same codebase out there ;)

![dlink_msearch_echo](https://cloud.githubusercontent.com/assets/497520/3292774/18df6b74-f593-11e3-9a09-2c91ea99d618.png)

if I remove it show options will not show me the RHOST anymore

```
msf > use exploit/linux/upnp/dlink_upnp_msearch_exec_echo
msf exploit(dlink_upnp_msearch_exec_echo) > show options

Module options (exploit/linux/upnp/dlink_upnp_msearch_exec_echo):

   Name   Current Setting  Required  Description
   ----   ---------------  --------  -----------
   RPORT  1900             yes       The target port
```