Shell Programming and Scripting

My English is no very good.
I must make a bash scripting sh create like a backdoor, and when execute the script a user without privileges convert in super user or root, whithout introducing the password.
In Spanish:
Crear un script que sirva como puerta trasera al sistema, de manera que al ejecutarlo, un usuario sin privilegios se convierta en superusuario, sin necesidad de introducir password.
I don´t know how to create it.
Please help me!!
Thanks

There is already something to do that, and it is controllable so all users cannot logon as root and trash the system.

The sudo command lets a user execute a command that requires privlieged access. The sudoers file controls who can use the sudo command and what the user can sudo to.

For example, you could set up kitievbr to use sudo to anything on the system, just like root. Or you could let kitievbr run useradd and nothing else. The file is /etc/sudoers on linux systems.

Consult your man page for sudo if you are working on a different system.