http://www.washingtonpost.com/blogs/the-switch/wp/2017/11/29/on-a-mac-running-high-sierra-update-now/ >Apple issued a patch Wednesday to fix a major flaw that allowed people to gain deep access to computers running its latest operating system without the need for login credentials. >Reports of the flaw began circulating Tuesday after security researchers found the vulnerability. The researchers reported that it was possible to gain access to a Mac — and its core settings — without having to use its owner's username and password. Instead, a potential hacker could type “root” into the username field of key settings in System Preferences menu without entering the password.