http://www.techradar.com/news/macos-high-sierra-security-flaw-gives-anyone-full-admin-access-no-password-needed

A Turkish software developer has publicly revealed via Twitter that he has uncovered a massive security bug in macOS High Sierra, Apple’s latest operating system. 

The flaw grants anyone using a Mac machine admin access by just clicking ‘other’ on the login screen and using ‘root’ as the username, no password needed.