Mediawiki DjVu RCE

This module exploits the recent Mediawiki disclosure. It is 'authenticated' but a lot of Wiki's are public registration :)

It requires some configuration of Mediawiki 

djvulibre-bin and netpbm need to be installed on the device

Setup for the configuration can be found here (copy and paste into LocalSettings.php):
https://www.mediawiki.org/wiki/Manual:How_to_use_DjVu_with_MediaWiki

Our testing was performed on Turnkey MediaWiki Appliance available: http://www.turnkeylinux.org/mediawiki So would be good to see if it works on other setups/versions!

I added a to_form_data to the MIME::Message as it seemed a bit messy to gsub (see multiple modules). This also prevents corrupting the binary. 

I got a bit carried away and didn't want to write some auto follow functionality that wasn't available to other modules, but I have structured it in a way that it really shouldn't affect anything unless the option is set for send_request_cgi.

The binary could be any valid djvu file. I dont think the exploit fires if its corrupt/invalid.