I’m trying out HA on a Raspberry Pi 3, and while trying to find how to shut it down without just disconnecting the power, found that if you switch to TTY2 (alt-F2) I could log in as root without a password.
Having done this, I was of course able to shut down with poweroff.
It’s a security hole, some people would be horrified, but maybe I’m over-reacting.
Thanks for the shutdown info, it wasn’t spelt out in the docs.