BSD tty security, part 3: How to Fix It

[Matt Ranney]

I've just joined this groups a few days ago, so I missed most of the
other things that were said, but the "write" program doesn't even need
to be used to fire anonymous messages to people.  You can just cat a
core dump > their tty.  

I'm sure this has been said before, but could someone please enlighten
me on a few things?  I still don't see why tty security is such a difficult
problem to resolve.  Why not make programs that need to spam the
user's tty setuid root, and change the default permissions on user's
ttys so that only they (and root, of course) have read/write.  And
make the write program, as was said before, spew data at a slower rate,
and prepend each line with the writer's id.  The login program is
already setuid root, so the permissions could stay at root r/w only.
This would fix programs like "cover" from working.

So why wouldn't this work?  If some other naive person like myself has
already asked this question and had it answered, please respond via Email.

Thanks
--
Matt Ranney -- t22918 at ursa.calvin.edu  
sendmail: error reading file /home/t22918/.signature     (core dumped)