Cross Site Scripting exploitation via malformed files

[Jerome ATHIAS <jerome.athias () free fr>]

It was publicly released on different forums (http://cyruxnet.org/foro/viewtopic.php?t=559); multiple webmail systems 
and websites are vulnerable to Cross Site Scripting via a malformed file.

A basic PoC :

Build a text file (ie: photo.txt)

<script language="Javascript">
alert('Vulnerable!');
</script>

then rename the file with the .jpg extension (photo.jpg), and send the renamed file as attachement by mail to the 
victim.

On many webmail systems, when the JPG file is downloaded, then the script is executed (you can play with javascript, 
vbscript,...)

It was verified under IE - XP SP2

So it opens a door for virus...


Regards and greetings to: ZaBoo, whitehat.co.il, Class101, Mandragore

Jerome ATHIAS