The patch is out.
https://support.apple.com/en-us/HT208315
The Twitter message was just the first person to "see" the true possibilities. The bug had been on Apple's fora for months, as a solution to a very specific problem. That poster didn't even see the possibilities.
A bug report had been filled about two weeks ago. I guess there's some backlog in reading these...
Another serious local problem is that any logged on user can kill everything via the Terminal. Apple doesn't see that as a bug, letalone a security problem. It's a feature!