[techtalk] no modem etc

[jenn at simegen.com]

dynamix at iinet.net.au wrote:
> 
> I have one problem and one question..
> the easy question first...
> If I go to shutdown i get asked for root's password.( i have set my user
> self as super user equiv).obviously a security feature..........
> BUT why can ANY user just go CTL-ALT-DEL and the machine will end
> processes
> and dismount etc and reboot....one can just hit the power button once it
> cycles out of the OS ....???Im a bit puzzled at what seems such an
> obvious way to beat security....
> Ive tired it on at least 4 different distro's....
> puzzled.............

There is no way the operating system can prevent someone at the 
console from shutting down the computer. 
Pulling the power cord, clipping the cable if need be, hitting the
machine with a sledgehammer - all of these work.

But requiring the user to be root to shutdown from a terminal IS a 
security feature - if Joe Average gets a shell account on your
machine, and SSHs or telnets in, he can't shut it down from under
you UNLESS he is also root.

Unix-based systems are designed to be multi-user, over multiple 
terminals. The special terminal 'console' has overriding powers.
On PC hardware, the keyboard and monitor plugged into the PC that's
running the OS is the console.



Jenn V.
-- 
       "Do you ever wonder if there's a whole section of geek culture 
		you miss out on by being a geek?" - Dancer.

jenn at simegen.com        Jenn Vesperman       
http://www.simegen.com/~jenn/