The weakness was published via Twitter yesterday. It remains unclear whether Apple has been notified before the existence of such a gap is announced to the public.
Usually when a weakness in the system is found, then the maker will be notified before the weakness is notified to the public. So far, Apple has a bug-hunting program, though participants can only participate if they get an invitation.
The process to take advantage of weaknesses in High Sierra is very easy, though fortunately this weakness is only found on the operating system. When this vulnerability in High Sierra is exploited, the user will automatically become System Administrator.
They will be able to see all existing files and that reset or change the password that has been used on that computer. The Apple ID email address on a Mac can also be deleted or changed.
Given how dangerous this weakness is, Apple should be able to release updates to fix it quickly since this issue has been published.
However, until now the company from Cupertino has not mentioned when they will release the update.
The best way to protect your computer now is to enable root password. You can do that by going to System Preferences> Users & Groups> Login Options> Join> Open Directory Utility> Edit. And active Root User.