Cross-site scripting (XSS) vulnerability in includes/flvthumbnail.php in the Youtube Gallery (com_youtubegallery) component 3.4.0 for Joomla! allows remote attackers to inject arbitrary web script or HTML via the videofile parameter.
Improper Neutralization of Input During Web Page Generation The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.