This was solved well before 2.1 shipped. The problem did exist in
2.0, but that's about a year old now, and has been replaced with 2.1.
Here's the log entry:
----
symbolic names:
OPENBSD_2_1: 1.16.0.2
OPENBSD_2_0: 1.11.0.2
...
revision 1.12
date: 1996/12/05 23:14:27; author: millert; state: Exp; lines: +14 -9
Stop info gathering attack pointed out by Alan Cox <alan@cymru.net>
Only return ENOENT if the dir trying to be mounted is really exported
to the client. Return EACCESS if not exported.
----
Now, if I remember, Alan had posted the information about this to
BUGTRAQ, thus prompting us to fix it (there is a small chance that the
problem report actually came to us via David Holland, though).
Anyways, this is not a new bug. (It's just that most people didn't
fix it).