How to disable the sudo password prompt

I asked this question over on SO and it got moved here. That said I no longer have the ability to edit the question as if I owned it, or even accept the correct answer, but this turned out to be the true reason why and how to solve it:

Found here User "rohandhruva" on there gives the right answer:

This happens if you change the hostname during the install process.

To solve the problem, edit the file /etc/hosts

127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 <ADD_YOURS_HERE> 
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 <ADD_YOURS_HERE>

It is not a security hole, at least no more than su is.

sudo is just of way for an administrator for having a quick root access without using a root shell (which can be dangerous).

sudo just requires the user to enter his own password and will indeed give him root access (try $ sudo whoami). However, not everyone should be in the /etc/sudoers file.

If you take a look at sudo manpage, you'll find how to limit sudo to some simple commands.

You can for instance, only allow the user bob to execute $ sudo poweroff without allowing him to do $ sudo cat /etc/shadow.

So no, it's not a security hole if you configure and use it correctly. If you don't want your users to have a root shell, think of forbidding commands like $ sudo su.