Charlie Miller, the one who discovered the hacking method, found out the fault saying “If you know the password you can control the battery” and hence the firmware can potentially hijack them to do anything the hacker wants to do. These hackers can cause a huge damage by ruining the battery or potentially allow malicious user to control the battery, causing it to refuse to charge, heat up until it explodes, or even run malware that infect your entire system no matter how many times you reinstall the software.
From examining Apple laptops, Miller noticed that all the embedded chips in the battery used the same default passwords. He discovered two distinct passwords after going over a 2007 MacBook battery software update. This means the hacker who knows the password can find a way to control the firmware and in turn manipulate the battery to wreak havoc your system.
A skilled hacker can do a trivial point of attack by going after a battery control chip, he can install all kinds of malware and it could be incredibly difficult to remove it from the system. The hacker can put the whole drive in, reinstall the software, flash the BIOS, and every time it would re-attack and screw you over. There is no way other than removing the battery and detecting the fault.
Hopefully,apple will issue an update soon after to protect MacBook users from malicious battery attack.Miller plans demonstrate a potential fix for this problem.