techtips@techtipsmaster~$ ){ :& };:

This statement is actually a infinite forking loop.The parent forks and new child processes are made.The newly defined function calls itself recursively due to ‘:’ and our system gets stuck when all resources are used up and insufficient for the new formed processes.so,once you typed this statement and hits ‘enter’,the only option is to restart your computer manually.’&’ will cause the forking to e continued in background.

Now,i will tell you how to play with some others computer.First you have to login to his account via ssh,(even guest account is sufficient with limited rights).

techtips@techtipsmaster~$ssh guest@192.168.40.3

password:******

guest@ssw9~$ ){ :& };:

Now,you can see your friend’s pc got stuck and you will see him,restarting the machine..enjoyed???this is a big security loop hole in linux machines.

but,i need to tell you one thing more.what will you do ,if your friend gets the trick and plays on you???

yeah…it is simple…

edit /etc/limits.conf using any editor in your root account and limit the total number of processed that all your users can have.so,after a limited processes by forking, your friend fails to do so since you are the master of tricks or techtipsmaster.