AVideo is a video-sharing Platform. Prior to 8.1.0, the anonymous login interface reflects request values into HTML and JavaScript without o

AVideo is a video-sharing Platform. Prior to 8.1.0, the anonymous login interface reflects request values into HTML and JavaScript without output encoding. In view/index.php, webSiteRootURL is returned verbatim by Streamer::getStreamerURL() in objects/Streamer.php and reaches navigation and form attributes; it also enters a single-quoted JavaScript string in view/index.header.php. It is not filtered by objects/security.php, while the user and pass fields are filtered only for single quotes, leaving double quotes and angle brackets capable of breaking out of their HTML attributes. In addition, view/index.header.php reflects POST fields using json_encode without JSON_HEX_TAG, allowing a closing script tag to break out, and locale/function.php stores the POST lang value in the session for unescaped reflection in view/index.php. An unauthenticated remote attacker who persuades a victim to open a crafted login link can execute arbitrary JavaScript in the encoder's origin. This can read the operator session identifier exposed in inline script, capture login credentials and perform actions as the operator against the encoder and its upstream platform. This issue is fixed in version 8.1.0.