SUDO - sudo: /etc/sudoers is mode 0755, should be 0440 error

Sudoers is a policy file to determine who and what you can run with sudo command. When sudo command is executed, it will check it permission and make sure it is only at read only mode 0440.

Sudoers file is owned by Root and should only be changed by Root. So, if you encounter error such as

sudo: /etc/sudoers is mode 0755, should be 0440

That means someone, most likely Root, had changed the permission of Sudoers file.

A lot of post said that you need reboot PC, boot into recovery mode, etc.. but they are overkill.

If you are a normal user, report this to your Root administrator.

If you have access to Root account, do the following

1. Login to Root as super user via su command. It will require you to enter Root password

su root

2. cd to /etc

cd /etc

3. Change the permission for the file

chmod 0440 sudoers

4. Exit super user mode

exit

That all. You do not need to reboot or boot into recovery mode at all.