Cardiac pacemakers are small devices that are implanted in a patient's upper chest to correct abnormal or irregular heart rhythms. Pacemakers are generally outfitted with small radio-frequency equipment so the devices can be maintained remotely. That way, new surgeries aren't required after they're implanted. Like many wireless devices, pacemakers from Abbott Laboratories contain critical flaws that allow hijackers within radio range to seize control while the pacemakers are running.

"If there were a successful attack, an unauthorized individual (i.e., a nearby attacker) could gain access and issue commands to the implanted medical device through radio frequency (RF) transmission capability, and those unauthorized commands could modify device settings (e.g., stop pacing) or impact device functionality," Abbott representatives wrote in an open letter to doctors.