The Foxtool All-in-One: Contact chat button, Custom login, Media optimize images plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 2.5.3. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with subscriber-level access and above, to modify arbitrary subkeys of the foxtool_settings option, including enabling site-wide SVG uploads by toggling the media-up3 key, which can facilitate stored cross-site scripting via malicious SVG files.