So, somehow one of the guys on my team messed up the sudoers file on a couple of VMs (all Ubuntu 18.04).
The files were truncated and the only line in them is:
nagios ALL=(ALL) NOPASSWD= ALL
su to the
nagios user and fix the sudoers file, except the
nagios user has no password assigned, and there is no root password defined. So that won't work.
Any ideas how to fix this?