[Semibug] OpenBSD - Authenticate boot into single user mode

Jonathan Drews jondrews at fastmail.com
Wed Jun 2 06:03:23 EDT 2021

Hi People:

  I have an OpneBSD laptop. I was distrurbed to find this:

I Forgot My Root Password

You boot into single user mode;
boot> boot -s

and now have root privliges and can change the root password!

My question is how do I prevent this? I thought of using a BIOS
level password. That would suspend the boot process until you
entered a password. However the thief could remove the CMOS battery
and the BIOS would reset.

How can I require authentcation on single user mode boot in OpenBSD?

Kind regards,


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