Expert Explains How Bluetooth is Used to Hack Devices

Bluetooth wireless technology for exchanging data between devices appeared in the 2000s and is today widely used around the world. However, convenient wireless connectivity also exposes users to potential critical vulnerabilities. Daniil Chernov, Chief Technical Officer at DerSecur LTD., shared how Bluetooth vulnerabilities can be exploited to hack devices, what functions and data can be accessed, and whether Bluetooth should be turned off when not in use.

Bluetooth supports two devices communicating and exchanging data. This is a common built-in technology in wireless devices: headphones, portable speakers, smart watches, keyboards, computer mice, multimedia systems, laptops, and desktops.

Replacing IrDA in the early 2000s, Bluetooth had a connection range of up to 10 meters. There were known dangers even back then, when hackers could gain access to phone services such as texting. Furthermore, a Bluetooth headset could be used to connect to a device and illegally eavesdrop on calls. As technology evolved, so did potential threats. In the 2010s, it was discovered that taking advantage of Bluetooth vulnerabilities could give control over a smartphone, which was exploited to massively spread worm viruses.

The latest and most critical Bluetooth vulnerability was detected in 2020 in Android devices and was called BlueFrag. This security breach compromises Android 8 Oreo or Android 9 Pie, allowing hackers to run any commands on devices remotely and steal data, while remaining within Bluetooth range. Moreover, since the launch of Bluetooth 5.0, this range can reach up to 100 meters.

Now, the Darknet sells zero-day vulnerabilities to compromise Android devices via Bluetooth. This type of vulnerability is special. Hackers detect it, use it only in an ad-hoc manner, and sell it for big bucks to peers. Zero-day is a dangerous vulnerability as it is unknown to the information security industry, which means there is no patch yet. Security updates thus only come out after the vulnerability has already been widely exploited.

Bluetooth security depends on both Bluetooth and device manufacturers, since they are responsible for creating connection rules. Some devices automatically pair and some require a password. For example, to connect Apple Watch and iPhone, you need to scan a sophisticated graphical code displayed on the watch screen, which significantly reduces the risk of a smartwatch being hacked and compromised.

Massive hacking via Bluetooth is not something to be concerned about. Bluetooth is not the most common hacking technique, as it has a number of practical limitations. For example, an attacker has to be within the range of a turned-on Bluetooth to make it work.

Moreover, as soon as a vulnerability becomes known, manufacturers promptly develop updates, which can be installed to protect users. Therefore, the ultimate rule is to promptly install software updates with security patches. Additionally, privacy settings can be configured so that only gadgets already connected to your device can detect it. New devices that haven't exchanged data with your device yet won't see it. Finally, you can protect your devices from unwanted Bluetooth intrusions by simply turning Bluetooth off when you don't use it.