macOS High Sierra may go down in the history books as Apple’s worst release of macOS since the initial one. Swapping the graphical user interface to use the Metal API wasn’t a smooth transition to say the least but the real mess is in regards to security. There was a bug where a user’s password could be displayed in the password hint field so logging in as a malicious user only requires entering a user’s password incorrectly to trigger the hint field. But yesterday it was revealed that the root account, which is normally disabled entirely, could be activated in High Sierra by simply typing root into the user name field in System Preferences:
The bug, discovered by developer Lemi Ergin, lets anyone log into an admin account using the username “root” with no password. This works when attempting to access an administrator’s account on an unlocked Mac, and it also provides access at the login screen of a locked Mac.
The only good news is that you can defend against this bug by enabling the root account and giving it a password.
The security mistakes in High Sierra are incredibly amateur. Automated regression testing should have caught both the password hint mistake and this root account mistake. I can only assume that Apple’s quality assurance department took the year off because both High Sierra and iOS 11 are buggy messes that should never have been released in the states they were released in.