go2rtc expands ffmpeg: sources into an exec: command line built from the
source's #key=value parameters, so the echo/expr/exec prefix check on
PUT /go2rtc/streams could be bypassed to run arbitrary ffmpeg arguments.
Sources submitted through the API now only accept the ffmpeg: parameters
the UI and docs use (video, audio, hardware with preset names, plus
numeric width/height/rotate/bitrate/timeout and async). Quotes,
whitespace, #raw, #input, #drawtext and unknown parameters are rejected
unless GO2RTC_ALLOW_ARBITRARY_EXEC is set. Sources defined in the config
file are unchanged.
Fixes GHSA-qjjw-3v66-279f
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
