An unauthenticated arbitrary file read is possible via ffmpeg argument injection through the query parameter parsing mechanism. The `ParseStreamOptions` method in `StreamingHelpers.cs` adds lowercase query parameters to a dictionary without validation, bypassing the RegularExpression attribute on the level controller parameter. This unsanitized value is then concatenated directly into the ffmpeg command line. An attacker can inject a drawtext filter with a textfile argument to read arbitrary server files, such as /etc/shadow, and exfiltrate the contents as text rendered in the video stream response. The affected endpoint is '/Videos/{itemId}/stream', which lacks an Authorize attribute, allowing exploitation without authentication, although item GUIDs are pseudorandom.