Exactly: trivial changes will protect you from script kiddies. Non-bypassability is required to protect you from determined attackers. It depends on your threat model: how much will a penetration event cost you? What is it worth to someone to hack you?Perhaps I'm the only one who feels this way, but I believe that the vast majority of the exploitation of systems is being performed by people with no knowledge of how to write an exploit and that the vast majority of exploits are fragile. Doing anything that makes you different from every other installation of Linux/HPUX/Solaris/InsertOSHere will drastically decrease the changes of any point and click exploit working against you.
Could a determined (and knowledgable) attacker still get through? Sure. But if we're talking protections that take very little effort to implement, have a minor performance impact and will save your skin some of the time, it's obvious that it's worth deploying them. As long as you're not kidding yourself that you're then totally secure.
Its kind of reminiscent of that old joke about the two guys running awayBut if you taste better (you are a bank and he is a basement RH box) then the lion may choose to chase you anyway.
from the lion. You don't have to beat the lion, just the other person.
Crispin
-- Crispin Cowan, Ph.D. http://immunix.com/~crispin/ Chief Scientist, Immunix http://immunix.com http://www.immunix.com/shop/
