WordPress Photo Gallery Plugin <= 1.8.21 Reflected Cross Site Scripting in editimage_bwg thumb_url

The thumb_url parameter of the AJAX call to the editimage_bwg action of admin-ajax.php is vulnerable to reflected Cross Site Scripting. The value of the thumb_url parameter is embedded within an existing JavaScript within the response allowing arbitrary JavaScript to be inserted and executed. The attacker must target a an authenticated user with permissions to access this component to exploit this issue.