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 privileges. 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 needed.
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.
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 'sudo' by doing one of the following
steps:
- *
- In a shell, do
sudo adduser username sudo
- *
- Use the graphical "Users & Groups" program in the
"System settings" menu to add the new user to the sudo
group.
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 sudo 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 them.
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 consider
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 here.
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
%sudo ALL=(ALL) ALL
to disable sudo access to members of the sudo group.
sudo(8), https://wiki.ubuntu.com/RootSudo