The Big Guide to Bluetooth Security

The Complete Guide to Bluetooth and Security
Signils is presents the big guide to Bluetooth security. This is a comprehensive look at the Bluetooth protocol from a security perspective.

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Bluetooth Security

When used with precautions, Bluetooth is a reasonably secure wireless technology. Bluetooth connections are encrypted so that casual eavesdropping from other nearby devices is prevented. Also, the frequency hopping technique prevents an easy invasion. You can limit Bluetooth connections by tapping into a variety of settings. There are two levels of Bluetooth security:

  1. Device-level security – you can trust another Bluetooth device to restrict connections to only that particular device.
  2. Service-level security – restrict any type of activity your devices are permitted to engage in when connected to another device.

There are some risks involved because hackers are becoming more sophisticated when it comes to deploying malicious attacks that use Bluetooth wireless networking. For an average person, there are limited security risks related to Bluetooth when used with safety in mind. That didn’t necessarily used to be the case but the security of Bluetooth has improved much since the early days of its introduction.  

Types of Bluetooth Attacks

The truth is that Bluetooth networks can be hacked. When someone says “hacking,” we usually think in terms of the Internet, servers, applications, and other computing devices. But smartphones can be hacked too, and hackers have different types of Bluetooth attacks at their disposal. In recent years, smartphone hacking has increased because phones have developed into such an advanced form of technology. We use our smartphones to do almost everything, from sending and receiving emails, downloading music and movies, social networking, online shopping to making financial transactions and managing our bank accounts. With such sensitive information stored in a pocket device, its no wonder they’ve become a target for hackers.

Hackers may hack a smartphone:

  • To eavesdrop on calls
  • To steal funds
  • To infect it with malware
  • To access personal information for blackmail

Devices that use an outdated version of Bluetooth (such as version 1, 2, or 3) are especially prone to attacks. The methods hackers can use to attack a device include:

  1. Bluebugging. Typically associated with older versions of Bluetooth, bluebugging is an attack centered on manipulating a device without the owner’s knowledge. Hackers can “bluebug” to eavesdrop on phone calls, connect to the Internet, send/receive text messages, or even make calls.

  1. Bluesnarfing. This is the most dangerous type of Bluetooth attack. Even if the Bluetooth on your smartphone is in invisible mode, it can still be attacked with the bluesnarfing method. However, being set on invisible mode makes it more difficult for them to figure out the model and name of your device. Attackers use this method when they want to access data on your phone. Such data can include addresses, calendar information, bank details, and IMEI (International Mobile Equipment Identity), which can be used to route your incoming calls to their cellphones. To protect your device from bluesnarfing, regularly update your device software and make sure that your Bluetooth is in invisible mode when in use. Also, switch it off when you’re not using it.

  1. Bluejacking. Bluejacking involves exploiting the Bluetooth electronic business card feature by using it as a message carrier. This way, the attacker can send offensive messages to any available devices located in the vicinity. The attacker needs to be within 10 meters of your device in order to hack it. This is not such a serious type of attack because your data is not in danger of being used or extracted. Put your smartphone in invisible or non-discoverable mode or disconnect immediately once you are done using the Bluetooth.

  1. Blueborne. If you’ve ever had a problem with malware taking control of your smartphone, you likely experienced a blueborne attack. Attackers infect a device with malicious code to take control of it. It works like an airborne virus – if a device is infected with this malware, it can infect any other devices it connects with using Bluetooth. Devices with outdated software and without VPNs are more vulnerable to blueborne attacks. If your smartphone is not up-to-date and you have a habit of leaving your Bluetooth on (even when not using it), your device is exposed to blueborne (as well as many other) attacks.

  1. App attack. Some smartphone apps make use of Bluetooth without the user’s knowledge. App manufacturers want to collect your data and track your location for their benefit. It doesn’t necessarily mean that the apps are unauthorized – they can be legitimate, like Facebook and YouTube.

  1. Denial of Service (DoS). A DoS is a type of attack involving an attacker pairing his or her Bluetooth device to another device, and it is the easiest attack hackers can perform. The damage is usually minimal because data is not jeopardized. Instead, a denial of service attack prevents the user’s ability to effectively use the device or service. Also, you may be able to see who is attacking you because it requires the attacker to be in your close proximity.

  1. Location tracking. People most prone to location tracking Bluetooth attacks are fitness enthusiasts. They are always connected to their Bluetooth devices because their wearables (e.g., fitness trackers) are used to track their fitness progress. Attackers who are interested in your location may hack your device.

  1. Car whisperer. When you buy a new car, you should change the manufacturer’s PIN on the Bluetooth-enabled entertainment system to avoid car whisperer Bluetooth attacks. This type of attack enables hackers to send/receive audio through your vehicle’s sound system.

In 2017, Armis Labs, an IoT-focused security company, revealed a blueborne attack that impacted billions of devices, including unpatched Windows, iOS10, Linux, and Android devices. Researchers at the CISPA (Center for IT-Security, Privacy, and Accountability) discovered a vulnerability in 2019 that they identified as a threat to the security of all Bluetooth users. They named it the Key Negotiation of Bluetooth attack or KNOB and said that it could be used to attack devices with Bluetooth versions from version 1.0 up to 5.1.

Bluetooth Security Measures

Bluetooth technology has been available for decades and, and even though it’s quite safe, hackers are still managing to find alternative ways to hack devices through the Bluetooth network. Considering the fact that people are using smartphones for tasks that are much more complex than messaging and calls (e.g., financial transactions), Bluetooth attacks could lead to serious issues.

To improve the security features of your Bluetooth connections, you should:

  • Ensure that you only connect to devices that use the latest Bluetooth version
  • Pair devices using “Passkey Entry” as opposed to “Just Works”
  • Use AES, DES, or Triple DES encryption keys
  • Make your device non-discoverable
  • Avoid connecting devices in public
  • Protect your important data using passwords
  • Update your device operating system and firmware
  • Make sure your devices use a recent Bluetooth version
  • Limit app permissions
  • Avoid ‘Just Work’ pairing whenever possible

Bluetooth Low Energy (BLE) Technology and Beacons

BLE beacons are beacons that communicate via BLE transmitters. These devices are actually small radio transmitters that can be strategically placed throughout different locations or given to people that broadcast Low Energy Bluetooth signals. The range of these signals depends on the hardware capability – a beacon can transmit BLE signals to 80 meters (on average), while the latest RuuviTag beacons can transmit signals up to 1 km. These signals are capable of triggering an action that’s relevant to the location.

BLE beacon use cases are found in:

  1. Asset tracking
  2. Hyperlocal check-in
  3. Indoor navigation
  4. Retargeting Ads
  5. Proximity marketing

RuuviTag beacons

RuuviTag low-energy sensor beacons are revolutionary in their respective field. Developed by a startup from Finland, these Bluetooth 5.0 beacons are open-sourced, have a range of 1 km in the open air, can measure humidity, air pressure, temperature, altitude, and acceleration. The technology offers unlimited possibilities for Bluetooth developers, educational institutions, healthcare providers, and IoT companies. To pull the data collected by a RuuviTag beacon to a smartphone, you don’t even need any pre-installed apps.

Almost every modern device out there comes equipped with Bluetooth technology, from smartphones to headphones, headsets, laptops, keyboards, fitness trackers, smartwatches, car accessories, IoT devices, etc. All these devices are easy to purchase (both offline and online), but before you buy one, there are some precautions you need to take.

Before getting a new Bluetooth-enabled device or engaging in a Bluetooth app-development project, you should know all the capabilities and possibilities that Bluetooth technology brings to the table in the year 2020.

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