AVideo has an OS Command Injection via $() Shell Substitution Bypass in sanitizeFFmpegCommand()

WWBN AVideo is an open source video platform. In versions up to and including 26.0, the sanitizeFFmpegCommand() function in plugin/API/standAlone/functions.php is designed to prevent OS command injection in ffmpeg commands by stripping dangerous shell metacharacters (&&, ;, |, ` `, <, >). However, it fails to strip $() (bash command substitution syntax). Since the sanitized command is executed inside a double-quoted sh -c context in execAsync()`, an attacker who can craft a valid encrypted payload can achieve arbitrary command execution on the standalone encoder server. Commit 25c8ab90269e3a01fb4cf205b40a373487f022e1 contains a patch.