@dangoodin Physical threat model is a separate concern, to me anyway. Though I can't think how an "evil maid" would succeed undetected vs various boot chain checks (incl open source ones like Qubes' anti-evil-maid; IIRC a fw boot logo would have to be included in both the sealing and measurement process).

Remote threats to a regular OS are a very big concern w something like this, because 1) typical OS protections are weak due to the kernel being very complex (just one priv escalation and they've got into your firmware) and 2) online system means many hours and avenues of opportunity throughout each day and 3) high value exploit bc its so privileged and hard to detect or remedy. Putting VM breakout requirement in their way is a game changer, IMO. #sanity

As for this particular class of exploit, malformed images, a permanent fix may be possible if an update including a setting to disable custom image, or perhaps a better parser that is formally verified. But you still have to wonder what else the fw may be parsing insecurely.