Security researcher Charlie Miller discovered a potential vulnerability affecting the batteries within select MacBook, MacBook Pro and MacBook Air models. The firmware on the chipset that controls the battery is secured with a single, easy to break default password. Once a hacker has this password, he could use it to manipulate the settings of the battery and possibly install malware that infects the computer every time it boots.
Miller discovered this vulnerability when Apple issued an update that included code for the battery. He figured out the two default passwords and was able to reverse engineer the firmware. He then rewrote it to do whatever he wanted. He plans to show off this hack at the upcoming Black Hat Conference in August.
This is more of an informative hack and not one likely to land on your computer. Thus far, Miller is the only one to discover this vulnerability and he is not releasing any details until next month. He also contacted Texas Instruments and Apple so a patch could be issued before the details of the hack goes public.