Researchers at Germany’s Technical University of Darmstadt have discovered a vulnerability in the Bluetooth chip of the iPhone. The flaw allows attackers to run malicious firmware on an iPhone device even when the device is turned off.

The malware allows attackers to track the location of the phone or perform new functions even when the device is off.

Research helps to unravel the dangers of the low power mode (LPM) that gives room for the flaw on Apple iPhones. When an iPhone is turned off, it is not shut down completely, but the device runs in a low-power mode, which allows it to perform some actions, including locating the device if it is lost.

“The current LPM implementation on Apple iPhones is opaque and adds new threats. Since LPM support is based on the iPhone’s hardware, it cannot be removed with system updates. Thus, it has a long-lasting effect on the overall iOS security model. To the best of our knowledge, we are the first who looked into undocumented LPM features introduced in iOS 15 and uncover various issues.,” the researchers’ paper states.

While the always-on feature on the iPhone offers immense usage, it can also be exploited by hackers. Aside from allowing malware to run while the iPhone is turned on, exploits targeting LPM could also enable malware to operate with much more stealth, since LPM allows firmware to save battery power.