Macs have the reputation that they "just work" and never have any security problems. Of course, we both know that they sometimes don't work and they still suffer from security flaws and viruses - just not as many as the typical Windows computer.
Well, get ready for another security flaw. This one could let a hacker take over your Mac.
The researcher who discovered it, Emil Kvarnhammar of TrueSec, calls it "rootpipe." Unfortunately, until Apple fixes it, he can't go into many details.
However, he does say that a hacker who gets access to your computer - either in person, remotely or with a virus - can take control of your account without needing a password. This means they can install software or change critical system settings.
This only appears to be a problem in OS X 10.10 Yosemite and a few earlier versions of OS X, like OS X 8.5. OS X 10.9 doesn't have this problem. Still, the following instructions are good for any Mac user to know.