A Review of Bluetooth Attacks and How to Secure Your Mobile Device

Keep your phone safe against Bluetooth vulnerabilities

Bluetooth is best known as the wireless technology that powers hands-free earpieces and connects your phone to audio, navigation, and electronics through the Internet of Things (IoT). As convenient as Bluetooth can be for productivity and comfort, it can also present major security risks. While most of the problems identified five to ten years ago have been resolved by now, some remain. And there's also good reason to be cautious about new, as-yet-undiscovered problems. 

Here are a few examples of the mobile security threats in which Bluetooth makes us vulnerable, along with tips to secure your mobile workforce devices.

General software vulnerabilities

Software in Bluetooth devices—especially those using the newer Bluetooth 5 specification—is not perfect. Really, it’s unheard of to find software that has zero security vulnerabilities.

As Finnish security researchers Tommi Mäkilä, Jukka Taimisto and Miia Vuontisjärvi demonstrated in 2011, it’s easy for attackers to discover new, previously unknown vulnerabilities in Bluetooth devices. Potential impacts could include charges for expensive premium-rate or international calls, theft of sensitive data or drive-by malware downloads.

To combat this threat: Switch off your Bluetooth when you’re not using it.

Eavesdropping

Bluetooth—named after the Viking king, Harald "Bluetooth" Gormsson, due to his work to unite different 10th-century European factions—is all about wireless communication. Bluetooth encryption is supposed to stop criminals listening in to your data or phone calls.

In other words, eavesdropping shouldn’t be a problem. However, older Bluetooth devices that use outdated versions of the Bluetooth protocol will likely face the threat of unpatched security holes.

To combat this threat: Ban devices that use Bluetooth 1.x, 2.0, or 4.0-LE and ensure devices use the latest versions and protocols.

Denial of service

Malicious attackers can crash your devices, block them from receiving phone calls and drain your battery.

To combat this threat: Again, switch off your Bluetooth when you’re not using it.

Bluetooth range is greater than you think

Bluetooth is designed to be a “personal area network.” That is to say: devices that are more than a few feet away should not be accessible via Bluetooth.

However, you’re not safe if you simply ensure there’s distance between you and a potential attacker; hackers have been known to use directional, high-gain antennas to communicate over much greater distances successfully. For example, security researcher Joshua Wright demonstrated the use of such an antenna to hack a Bluetooth device in a Starbucks from across the street.

To combat this threat: Once again, switch off your Bluetooth when not in use!

Bluetooth headsets

Wright has also demonstrated serious flaws in many popular Bluetooth headsets. By exploiting these vulnerabilities, attackers can eavesdrop on your conversations with the people around you, not just your phone calls. Built-in hands-free car kits can also be vulnerable.

The device becomes, in effect, a mobile bugging device, transmitting everything it hears to an attacker.

To combat this threat: Make sure you change the default PIN code to something hard to guess. And (you guessed it) switch off your Bluetooth.

See the bigger picture

It’s vital to develop and communicate company policies for mobile device security—including Bluetooth—so that your business’ data isn’t compromised, and your end users can work safely when mobile. Keep in mind, mobile devices present a variety of risks that need to be addressed, and Bluetooth security is just one often-overlooked piece of the mobile security puzzle. Be sure to include mobile device security as part of your overall cybersecurity strategy, for both home and business protection.

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