One of the most famous Linux debates on the internet is over Ubuntu's security model of using sudo to administrate a machine and disabling the traditional root login via su.

Enabling the root account in ubuntu is rarely necessary. Almost everything you need to do as root of an Ubuntu system can be done via sudo or gksudo. If you really need a persistent root login, the best alternative is to simulate a root login shell using the following command... It is tested in ubuntu 9.10 Karmic Koala also.

By default, the root account password is locked in Ubuntu - Canonical neither supports nor advocates enabling the root account. This means that you cannot login as root directly or use the su command to become the root user. However, since the root account physically exists it is still possible to run programs with root-level privileges.

In Ubuntu gksu and sudo can be hijacked by an attacker who already has access to the current non-administrative account.

Today, I did a fresh installation of Ubuntu 9.04 inside virtual box. My original idea was to play with sudoers and sudo command. I edited /etc/sudoers and logged out. Next time I tried to sudo , I go some parse error in /etc/sudoers. I was stuck . I needed sudo for modifying the file. But sudo was preventing me because of the error.

Ubuntu's use of sudo to simplify Linux administration is ingenious, but barely scratches the surface of what sudo can do. Follow along as Yvo Van Doorn of Likewise Software unlocks the powers of sudo.

The consensus among new Unix and Linux users seems to be that sudo is more secure than using the root account, because it requires you type your password to perform potentially harmful actions. In reality, a compromised user account, which is no big deal normally, is instantly root in most setups.

A security issue affects the following Ubuntu releases:
Ubuntu 6.06 LTS Ubuntu 8.04 LTS Ubuntu 8.10 Ubuntu 9.04 Ubuntu 9.10

If you are new to Ubuntu and have been using other distros like Fedora or openSUSE before, then you may find it frustrating that when you issue the "su" command it will result to authentication failure.By default, access to root account password is disabled in Ubuntu for added security measures.