The FooGallery plugin for WordPress is susceptible to a security vulnerability called Cross-Site Scripting. This vulnerability affects versions 1.9.24 and earlier of the plugin. It allows attackers, who are logged in to the website, to inject web scripts into pages that will run when those pages are accessed by other users. This occurs because the plugin does not properly sanitize the image title and caption parameters in the gallery media upload editor, or properly escape the output.