Complacency and incompetence are the biggest computer security threats, and Apple’s latest Mac security flaw seems to combine both of these. The flaw means anyone with physical access to your Mac can get inside the machine and tinker with it.
UPDATE (29 November 9:30am PDT): Apple has issued an apology and a patch to rectify this problem, more details here.
What’s the problem with macOS High Sierra?
The problem (which first got disclosed here) was first revealed in a Tweet by Lemi Orhan Ergin, who wrote: