Bugtraq: Re: how to trick most of cms avatar upload filter [exemple for : RunCms (PoC)]

[Taneli Leppä <taneli () crasman fi>]

Taneli Leppä kirjoitti:
> > then you need to take a good file editor , like: notepad++ (you can 
> > take whatever picture , and edit it without destroying it .)
> > we need to put some php code AFTER the picture code . when  it's done 
> > , try the picture if it still work , if yes , we are ok :).
> This actually seems to work. A quick workaround is to disable PHP in the
> directory where the avatar images are stored (or any user-uploaded files
> for that matter) in Apache:
>
> <Directory "/var/www/html/forum/avatardir">
>   php_admin_flag engine off
> </Directory>
Actually, your exploit only works if the avatar system strips the
.jpg extension for some reason. Unless you have configured .jpg
as a valid extension to be executed through PHP. But the above
still stands as a valid precaution for user uploaded material.

--
  Taneli Leppä         | Crasman Co Ltd
  <taneli () crasman fi>  | <http://www.crasman.fi/>