Re: Surprise null root password

David Chisnall <theraven@FreeBSD.org> writes:
> There was a very nasty POLA violation a release or two ago.  OpenSSH
> defaults to disallowing empty passwords and so having a null password
> was a convenient way of allowing people to su or locally log into that
> user but disallowing ssh.  This option does not work in recent
> versions of FreeBSD.  Turning on the option to permit root login while
> keeping the root password blank used to be (mostly) safe because it
> permitted su to root from people in the wheel group, root login via
> SSH key remotely (for ‘everything is broken I can’t log in as a user
> whose home directory is not on the root filesystem’ recovery) and
> local login as root from consoles marked as secure.  It now permits
> root login from the network with a blank password.

That is incorrect.  PermitRootLogin defaults to “no” in FreeBSD and to
“prohibit-password” upstream (and presumably in the port), while
PermitEmptyPasswords defaults to “no” both in FreeBSD and upstream,
cf. crypto/openssh/servconf.c (search for “permit_root” and
“permit_empty”).

DES
-- 
Dag-Erling Smørgrav - des@FreeBSD.org