Secure temporary files in Linux (ZDNet India)

I dont' think its a issue of preventing a bot creating a executable, but preventing the bot
getting on 
the system in the first place.

Lots of exploits out there target webapps, and bot/worm authors know that regardless of what 
distribution the target systems are running, /tmp is always available and writable... so thats
where 
they dump their bots and then execute them. (for good, well documented examples, have a look
at 
the phpbb worms that were around about a year ago..)

The noexec might stop 1/2 (guestimate) of existing bots/worms out there, but then there are
tons 
of perl or shell based bots as well that it probably wont stop.

To me, this is more of a problem of lazy admins looking for easy ways out. As long as you keep
you 
systems up todate then you shouldn't need to worry about bots targetting /tmp in the first
place 

(of course, its a different story for webhosts, but then this type of stuff is part of the
game)