Input validation vulnerability in Popup box 3.7.2

The Popup Box plugin for WordPress is vulnerable to a type of security attack called Stored Cross-Site Scripting. This vulnerability affects versions up to and including 3.7.1. It allows attackers with administrator-level access to inject malicious code into web pages. This code could then be executed whenever a user visits those pages. This vulnerability only affects multi-site WordPress installations, and those where a specific security setting (unfiltered_html) has been disabled.