How to Enable Root User on Ubuntu 24.04

Enable root

To enable the root user on Ubuntu 24.04, you open a terminal and set a password for the built-in administrator account. Setting that password is what unlocks the account. After that you can log in as root directly whenever you need to do advanced administrative work.

The first step is to get an administrator shell with the sudo -i command. Then you set a strong password for root. Pick something long and unique, because anyone who knows it gets full control of the machine.

1. Press Ctrl+Alt+T to open a terminal, or search for Terminal in the Activities overview.
2. Run the sudo command shown below.

sudo -s

The terminal asks for your current password. This is the password of your own user account, not the root password, which does not exist yet. Type it and press Enter. Nothing appears on screen while you type, not even dots. That is normal, so keep typing and press Enter when you are done.

Next, run the command that sets the root user’s password. It works from your sudo session, so it does not ask for a root password first.

sudo passwd root

1. Type the new password for the root account when the terminal asks for it, then press Enter.
2. Type the same password again to confirm it, then press Enter.

Again, nothing is shown while you type. If the two entries do not match, the terminal tells you the passwords do not match and you have to run the command again. When it works, you see a message that the password was updated successfully.

New password: 
Retype new password: 
passwd: password updated successfully

Setting the root password enables the account automatically. No restart or logout is needed. To undo this later, lock the root account again with the lock option of the passwd command (see its man page). Ubuntu then goes back to its default state.

Now switch your active shell to the root user.

1. Run the command shown below.
2. Enter the root password you just created when the terminal asks for it.

The prompt changes after a successful switch. It begins with "root" and ends with "#" instead of the usual "$". That is your confirmation that every command now runs with the highest level of system privileges, with complete control over the whole Ubuntu 24.04 system. Be careful what you type here. When you finish, close the root shell by typing exit and pressing Enter, which returns you to your normal user.

root@Ubuntu:~# 

Restrict the su command

Once root has a password, any local user who learns or guesses it can use the su command to become root. To reduce that risk, you restrict su by editing the Pluggable Authentication Modules (PAM) configuration file for switching users. The change forces users to belong to a specific security group before they can run su. Everyone else is refused, even if they know the password. The edit is a small change to one text file in the terminal.

Run the command below to open the su configuration file. You need sudo rights for this, because the file is owned by root.

nano /etc/pam.d/su

1. Find the line highlighted in the screenshot below.
2. Remove the # at the start of that line to uncomment it.

The line should now start with the module name and no hash symbol. Leave the rest of the file as it is.

# Uncomment this to force users to be a member of group adm
# before they can use `su'.
 auth       required   pam_wheel.so group=adm

Save your changes and exit the editor. If the file opened in nano, press Ctrl+O, then Enter to write the file, and Ctrl+X to close it. The change takes effect immediately, with no restart.

With the restriction active, only members of the adm group can use the su command. To allow a user to switch to the root account, add that user to the adm group with the command below. The user has to log out and back in before the new membership applies. Add only people you trust, because membership in this group lets them attempt to become root.

usermod -aG adm richard

The configuration is finished. Root has a password, and only members of the adm group can use su to reach it.

Summary:

Root access gives total control over every file and service on the machine. Treat the account with care, and use it only when a task really needs it, to keep the operating system stable.

• The root account offers full administrative access and can perform any task on the system.
• By default, the root account is locked to enhance security.
• You can enable the root account with the sudo command, which sets a password for it.
• Limiting the use of the su command helps prevent unauthorized access to the root account.
• Only add trusted users to the adm group to maintain system integrity.
• Review user permissions and access to the root account regularly to ensure ongoing security.