Security HOLE

Hello I recently bought 7.1 pro and forgot my root password. It was terrible. Anyway, after a bit thinkin' I took out the CD 2 and started the 'rescue system'. With that I had FULL ACCESS on MY HDDs!! Even /etc/pwd... . I created a new user with no password and root privileges. With that I edited the root pwd and ... ping-- There is my new root pwd. Isn't this a security hole. Let's say Microsoft's WEB-Server's runnin' Linux and I would have 10 Minutes physical access and my CD 2 with me. Then I could change the ROOT pwd. Sascha