I installed ubuntu 18.04 on an AWS instance, and accessed it via a putty session as ubuntu (using the AWS generated key).
I wanted to allow password based login, and I modified the ssh_login and sshd_login to allow password based authentication.
Then I screwed up, and manually edited the /etc/sudoers files
sudo vi sudoers
and saved the file. I made a syntax error in sudoers. I am now stuck.
Yes, I should have used pkexec visudo, but I did not. Any idea how to fix this? This is a remote system, so I cannot reboot in debug mode, or use a USB to reboot.