[gammafactor]

Unfortunately, and this goes for pretty much every UNIX out there with hardened (grsec) linux as possible exception, not just OSX, once someone has a local user on your machine, it's trivial to get root. On OSX, you don't even need a local privilege escalation exploit, so many other ways based on the way subsystems interact together.

If you want robust security, you will need to forget about OSX/BSD/Linux and look at Qubes OS. It's the best we have right now and nothing else comes close. Alternatively, compartmentalize and segregate (at the hardware level, all virtual machines have tons of host escalation bugs) and accept the fact that you will get owned.

[yurish]

Can you give examples of how on Unix systems you can get root access having a local user account?

[nsgi]

See http://theinvisiblethings.blogspot.com/2011/04/linux-securit...