Home Linux Tips & Tricks How To Restore Sudo Privileges To A User In Ubuntu Linux

How To Restore Sudo Privileges To A User In Ubuntu Linux

A Step-by-Step Guide to fix broken sudo in Ubuntu and its dervatives.

By sk
Published: Updated: 26.7K views

This tutorial explains how to restore sudo privileges to a user from recovery mode on Ubuntu Linux and its derivatives like Linux mint, Pop OS operating systems. This guide is official tested on Ubuntu 18.04 LTS system. However, It should work on newer Ubuntu versions and also on other Linux distributions as well.


The other day I was testing how to add a regular user to sudo group and remove the given privileges to make him again as a normal user on Ubuntu.

During my testing, I intentionally removed my administrative user from the 'sudo' group. As you may be aware, being a member of the sudo group is crucial for performing any administrative tasks. Unfortunately, I had only one super user, and I had already revoked their sudo privileges.

Every time I attempted to execute a command with the 'sudo' prefix, I encountered an error message stating, "sk is not in the sudoers file. This incident will be reported."

I am currently unable to perform any administrative tasks as I cannot switch to the root user by using the 'sudo su' command. It is worth noting that the root user is disabled by default in Ubuntu, which means I cannot log in as the root user either.

Have you ever been in a situation like this? No worries! Today, I will show you how to fix broken sudo privileges to a user on a Ubuntu  Linux system.

Restore Sudo Privileges to Users in Ubuntu

Step 1: Boot your Linux system into recovery mode.

To do so, restart your system and press and hold the SHIFT key while booting. You will see the grub boot menu. Choose "Advanced options for Ubuntu" from the boot menu list.

Choose Advanced options for Ubuntu in Grub
Choose "Advanced options for Ubuntu" in Grub menu

In the next screen, choose "recovery mode" option and hit ENTER:

Choose recovery mode in Grub menu
Choose recovery mode in Grub menu

Next, choose "Drop to root shell prompt" option and hit ENTER key:

Choose drop to root shell prompt option
Choose "Drop to root shell prompt" option

You're now in the recovery mode as root user.

Ubuntu recovery mode
Ubuntu recovery mode

Step 2: Mount root file system in read/write mode. To do so, type the following command to mount root (/) file system in read/write mode.

mount -o remount,rw /

Step 3: Now, add the user that you removed from the sudo group.

In my case, I am adding the user called 'sk' to the sudo group using the following command:

adduser sk sudo
Restore sudo privileges to a user from Ubuntu recovery mode
Restore sudo privileges to a user from Ubuntu recovery mode

Step 4: Then, type exit to return back to the recovery menu. Select Resume to start your Ubuntu system.

Resume normal boot
Resume normal boot

Press ENTER to continue to log-in normal mode:

Exit recovery mode in Ubuntu
Exit recovery mode in Ubuntu

Step 5: Now check if the sudo privileges have been restored.

To do so, type the following command from the Terminal.

$ sudo -l -U sk

Sample output:

[sudo] password for sk: 
Matching Defaults entries for sk on ubuntuserver:
env_reset, mail_badpass,

User sk may run the following commands on ubuntuserver:

As you see in the above message, the user sk can now run all commands with sudo prefix. Congratulations! You have successfully restored the sudo privileges to the user.

There are also other possibilities for causing broken sudo

Please note that I actually did this on purpose to show you how to restore broken sudo privileges to a user. I removed myself from the sudo group and fixed the broken sudo privileges as described above.

Don't do this if you have only one sudo user. And, this method will work only on systems that you have physical access. If it is remote server or vps, it is very difficult to fix it. You might require your hosting provider's help.

Also, there are two other possibilities for causing broken sudo.

  • The /etc/sudoers file might have been altered.
  • You or someone might have changed the permission of /etc/sudoers file.

Fix Broken Sudo in Ubuntu

If you have done any one or all of the above mentioned things and ended up with broken sudo, try the following solutions.

Solution 1:

If you have altered the contents of /etc/sudoers file, go to the recovery mode as described earlier.

Backup the existing /etc/sudoers file before making any changes.

cp /etc/sudoers /etc/sudoers.bak

Then, open /etc/sudoers file:


Make the changes in the file to look like this:

# This file MUST be edited with the 'visudo' command as root.
# Please consider adding local content in /etc/sudoers.d/ instead of
# directly modifying this file.
# See the man page for details on how to write a sudoers file.
Defaults env_reset
Defaults mail_badpass
Defaults secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin"

# Host alias specification

# User alias specification

# Cmnd alias specification

# User privilege specification

# Members of the admin group may gain root privileges
%admin ALL=(ALL) ALL

# Allow members of group sudo to execute any command

# See sudoers(5) for more information on "#include" directives:

#includedir /etc/sudoers.d

Once you modified the contents to reflect like this, press CTRL+X and y to save and close the file.

Finally, type exit and select Resume to start your Ubuntu system to exit from the recovery mode and continue booting as normal user.

Now, try to use run any command with sudo prefix to verify if the sudo privileges are restored.

Solution 2:

If you changed the permission of the /etc/sudoers file, this method will fix the broken sudo issue.

From the recovery mode, run the following command to set the correct permission to /etc/sudoers file:

chmod 0440 /etc/sudoers

Once you set the proper permission to the file, type exit and select Resume to start your Ubuntu system in normal mode. Finally, verify if you can able to run any sudo command.


In this guide, we have looked at what causes broken sudo, and how to restore sudo privileges to a user from recovery mode in Ubuntu and its derivatives.

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1 comment

lucas May 21, 2020 - 1:18 am



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