sudo_root - How to run administrative commands
By default, the password for the user "root" (the system administrator) is locked. This
means you cannot login as root or use su. Instead, the installer will set up sudo to allow
the user that is created during install to run all administrative commands.
This means that in the terminal you can use sudo for commands that require root privi-
leges. All programs in the menu will use a graphical sudo to prompt for a password. When
sudo asks for a password, it needs your password, this means that a root password is not
To run a command which requires root privileges in a terminal, simply prepend sudo in
front of it. To get an interactive root shell, use sudo -i.
ALLOWING OTHER USERS TO RUN SUDO
By default, only the user who installed the system is permitted to run sudo. To add more
administrators, i. e. users who can run sudo, you have to add these users to the group
'admin' by doing one of the following steps:
* In a shell, do
sudo adduser username admin
* Use the graphical "Users & Groups" program in the "System settings" menu to add the new
user to the admin group.
BENEFITS OF USING SUDO
The benefits of leaving root disabled by default include the following:
* Users do not have to remember an extra password, which they are likely to forget.
* The installer is able to ask fewer questions.
* It avoids the "I can do anything" interactive login by default - you will be prompted
for a password before major changes can happen, which should make you think about the
consequences of what you are doing.
* Sudo adds a log entry of the command(s) run (in /var/log/auth.log).
* Every attacker trying to brute-force their way into your box will know it has an account
named root and will try that first. What they do not know is what the usernames of your
other users are.
* Allows easy transfer for admin rights, in a short term or long term period, by adding
and removing users from the admin group, while not compromising the root account.
* sudo can be set up with a much more fine-grained security policy.
* On systems with more than one administrator using sudo avoids sharing a password amongst
DOWNSIDES OF USING SUDO
Although for desktops the benefits of using sudo are great, there are possible issues
which need to be noted:
* Redirecting the output of commands run with sudo can be confusing at first. For instance
sudo ls > /root/somefile
will not work since it is the shell that tries to write to that file. You can use
ls | sudo tee /root/somefile
to get the behaviour you want.
* In a lot of office environments the ONLY local user on a system is root. All other users
are imported using NSS techniques such as nss-ldap. To setup a workstation, or fix it,
in the case of a network failure where nss-ldap is broken, root is required. This tends
to leave the system unusable. An extra local user, or an enabled root password is needed
GOING BACK TO A TRADITIONAL ROOT ACCOUNT
This is not recommended!
To enable the root account (i.e. set a password) use:
sudo passwd root
Afterwards, edit the sudo configuration with sudo visudo and comment out the line
%admin ALL=(ALL) ALL
to disable sudo access to members of the admin group.
February 8, 2006 sudo_root(8)