So it looks like a glaring and brutal flaw has been exposed in High Sierra which allows root access with a blank password.
https://www.theregister.co.uk/2017/11/28/root_access_bypass_macos_high_sierra/
https://www.macrumors.com/2017/11/28/macos-high-sierra-bug-admin-access/
Anyone running High Sierra should address this ASAP to secure their Apple computer...
Someone will be getting fired for this one surely!