There's a security flaw in certain kinds of software that makes many web connected devices like smart thermostats, security cameras and more vulnerable.
It's called "Shellshock" and the flaw allows the user to gain remote control of a computer or system.
The problems affects devices running Linux and Unix operating systems and Apple's OS X.
That's the operating system used on Apple's MacBook laptops, iMac, Mac Pro and Mac Mini desktop computers.