Input validation vulnerability in Popup box 3.7.1

The Popup Box plugin for WordPress is vulnerable to malicious code being stored in it, which could be used to attack your website. This only affects multi-site installations, as well as installations where extra security measures have been taken to protect against malicious code. Versions up to 3.7.0 of the Popup Box plugin are vulnerable, due to a lack of protection against malicious code. Any user with administrator-level permissions or higher could inject malicious code into the plugin, which would then be executed when someone visits the infected page.