Video Thumbnails <= 2.12.3 - Admin+ Stored XSS

The plugin does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup).

Put the following payload in the "Custom Field (optional)" settings of the plugin: 123" onmouseenter=alert(/XSS/) "

The XSS will be triggered when accessing the settings page again and moving the mouse over the input box