What Is Bluesnarfing?

Date First Published: 11th May 2022

Topic: Computer Networking

Subtopic: Data Transmission Technologies

Article Type: Computer Terms & Definitions

Difficulty Level: 5/10

Learn more about what bluesnarfing is in this article.

Bluesnarfing is a type of attack where a malicious hacker gains unauthorised access to personal information and data on a device through a Bluetooth connection, such as text messages, photos, videos, calendars, emails, and contacts without the user’s permission. This is usually performed by exploiting vulnerabilities in Bluetooth and is a very harmful attack, since it can result in data theft as the data on the device may contain private information, such as private emails, photos, and videos. However, it is not as harmful as bluebugging, where a malicious hacker establishes a backdoor on a user's device, allowing them to take over and gain remote access to a device through a Bluetooth connection.

Note:

The term ‘bluesnarfing’ is a combination of the terms ‘Bluetooth’ and ‘snarfing’. The term ‘snarf’ means to copy a file or data over a network without appropriate permission.

Almost all mobile devices must be paired in order for data to be copied from them. In the past, there have been cases of devices being bluesnarfed without pairing being allowed. After mobile phone manufacturers became aware of this vulnerability, they released security patches for Bluetooth implementations and very few mobile devices are known to be vulnerable to bluesnarfing without the device being paired to it, unless a brute-force attack is performed.

How To Prevent Bluesnarfing?

A device must have a Bluetooth connection turned on and set to discoverable in order for it to be vulnerable to bluesnarfing. A device that uses an unsecured wireless network, such as in a shop or an airport is much more vulnerable to bluesnarfing. Bluesnarfing can be prevented by:

• Turning off discoverable mode and setting the device to ‘hidden’. This will greatly reduce the chance of a device being bluesnarfed, since compatible Bluetooth devices can be used, but other Bluetooth devices cannot discover them. However, a device that is set to ‘hidden’ may still have a very slight possibility of being bluesnarfed by guessing the MAC address of the device through a brute-force attack. MAC addresses are made up of 48 bits with 24 bits assigned to the manufacturer. There are 16.8 million possible combinations in the remaining 24 bits, requiring approximately 8.4 million attempts to guess the MAC address by a brute-force attack. The only way to completely safeguard a device from bluesnarfing is to turn Bluetooth off.
• Not connecting or pairing to unknown Bluetooth devices. It might be a device that performs malicious actions, such as collecting sensitive information.