Re: Wordpress 2.3 Cross Domain Content Insertion- New vulnerability + exploit - xssworm.com

[dave-san <dave () subverted org>]

Comments inline..

XSS Worm XSS Security Information Portal wrote:
> *0day XSS Exploit for Wordpress 2.3* – wp-slimstat 0.92 – [xssworm.com]
>
> Source:
> http://xssworm.blogvis.com/13/xssworm/0day-inject-exploit-for-wordpress-23-xsswormcom-all-version-vulnerable-with-no-patch/
>
> There is a serious holes in wordpress 2.3 that can be used with XSS by a
> blackhat hacker to attack the wordpress administrator and steal cookies from
> blogmins. This attack is known as 0day because it has just been reported to
> public and this is first day of public vulnerability, and *0day means
> 'published.*'
> Proof of concept:
>
> http://wordpress-web-blog.com/wp-admin/index.php?page=wp-slimstat/wp-slimstat.php?panel=1&fi=/feed/&ff=1&ft=<xss
> shellcode>

Hmm.. XSS shellcode? That's a new one for me. I'll take this to mean the 
injected script. From your post, I don't think you mean "shellcode" in 
the traditional sense.

> This attack to be used against wordpress web blog blogmin to steal
> blogosphere token to hack blogs. Of course we have included exploit code for
> this bug at the below.
>
> We have looked at coding for wp-slimstat but we cannot see any problem with
> input validating. Maybe some of the xssworm.com readers can show us where
> problem is in the php code because we cannot see any porblem here:
>
> –snips:
>
> C:\temp>findstr GET wp-slimstat.php
> $myFilterField = intval( $_GET['ff'] );
> $myFilterType = intval( $_GET['ft'] );
> $myFilterString = $_GET['fi'];
> $myFilterInterval = $_GET['fd'];
> $myFilterField = intval( $_GET['ff'] );
> $myFilterType = intval( $_GET['ft'] );
> $myFilterString = $_GET['fi'];
> $myFilterInterval = $_GET['fd'];
> '.(!empty($myFilterString)?'— <a
> href="?page='.$_GET['page'].'&panel='.$_GET["panel"].'">'.__('Reset
> filters', 'wp-slimstat').'</a>':").'
> <input type="hidden" name="page" value="'.$_GET['page'].'" />
> <input type="hidden" name="panel" value="'.$_GET["panel"].'" />
> <input type="hidden" name="fd" value="'.$_GET["fd"].'" /></form>';

It's late, and I might have missed something, but from the above, I 
don't see where the vulnerable parameter is being written back to the 
HTML response. Therefore, I don't think there is enough code in the 
lines above to locate the entire issue (though it looks like other 
parameters are vulnerable too). You mentioned:

  ft=<xss shellcode>

So, in this example, "ft" is the vulnerable parameter. Trace what 
happens in code with that parameter after it receives input. I'd guess 
that there is something like..

   echo '<maybe some HTML crap here>'. $myFilterType .' more...

or

   echo '<ditto>'.$_GET["ft"].'<ditto>..

Perhaps take a look at where they missed the output formatting/encoding 
for HTML. I may be so bold as to suggest that the lack of output 
encoding is the major reason that XSS exists.

> –snips
>
> With programmor using $_GET variable from user into echo into html output
> maybe php automatic GET validation filtering is not working for security? We
> are not programmers of php so we cannot see any porblems here as bug are too
> complex to understand.
> Many thanks for your comments on this vulnerability in wordpress 2.4

..edit

> Thanks vaj

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