Google is warning that the Bluetooth Low Energy version of the Titan security key it sells for two-factor authentication can be hijacked by nearby attackers, and the company is advising users to get a free replacement device that fixes the vulnerability.
A misconfiguration in the key’s Bluetooth pairing protocols makes it possible for attackers within 30 feet to either communicate with the key or with the device it’s paired with, Google Cloud Product Manager Christiaan Brand wrote in a post published on Wednesday.
The Bluetooth-enabled devices are one variety of low-cost security keys that, as Ars reported in 2016, represent the single most effective way to prevent account takeovers for sites that support the protection. In addition to the account password entered by the user, the key provides secondary “cryptographic assertions” that are just about impossible for attackers to guess or phish. Security keys that use USB or Near Field Communication are unaffected.