New Hacking Tools Bite Bluetooth

If Bluetooth headsets and mice are decluttering the wiring in your organization, take note: Researchers have unleashed two new Bluetooth hacking tools.

One tool -- Hidattack -- let attackers hijack a Bluetooth keyboard, and the other, BTCrack, could give an attacker full access to two connected Bluetooth devices. Both hacking tools were released last week at the Chaos Communications Congress hacker conference in Berlin.

Security researchers haven't given Bluetooth security a lot of attention to date, mostly because hacking Bluetooth requires the attacker be in close proximity to his or her victim, according to Rob Enderle, president and principal analyst with the Enderle Group. "Bluetooth is most commonly used for phone headsets, though increasingly it is being used for accessories [such as] wireless docking stations for laptops. As more and more confidential data is pushed through this technology, the concerns surrounding what can leak are increasing."

But Bluetooth security still isn't as much of a risk as user authentication and wide area network security, Enderle says, which are still much more likely to be exploited.

"While the [Bluetooth] exposure today is relatively trivial for the majority of folks, for those that have a high security requirement, this now is worth looking at, and the risk is increasing," he says.

Hidattack was developed by Collin Mulliner, a computer science student and researcher. Mulliner says he developed the attack tool accidentally while building a virtual Bluetooth keyboard. Hidattack basically attacks the Bluetooth human interface driver (HID) protocol.

"An attacker Bluetooth 'scans' for a PC in an interesting location, say, in a bank, which has an active Bluetooth HID driver running," Mulliner explains. "Once he finds a victim PC, the attacker's PC becomes a Bluetooth keyboard, which basically is like sitting in front of the victim's PC. The attacker now has full control and therefore can do whatever he wants."

But successfully executing such an attack would be difficult, he notes, and the most likely attack would be denial-of-service. The best way to protect against such an attack, Mulliner says, is to make the Bluetooth-enabled PC or laptop "non-discoverable" or to turn on Bluetooth authentication for HID devices.

BTCrack, meanwhile, builds on some previous Bluetooth vulnerability research that demonstrated how an attacker could grab a Bluetooth PIN during the so-called "pairing" process between two Bluetooth devices. Thierry Zoller, the creator of BTCrack and a security consultant at n.runs AG, says the tool takes advantage of weak PINs in Bluetooth devices. He says he's mostly come across implementations that use only digits, so it's easy to crack the PIN.

The tool would let an attacker that grabs the PIN to calculate the link key and decrypt the victim's traffic and gain full access to each of the connected Bluetooth devices, for instance, he says. An attacker could also plant a rogue link key on a workstation and have his own "remote hidden and encrypted stealth channel to that machine over Bluetooth," says Zoller, who says the main reason he did the Bluetooth presentation was that enterprises basically ignore Bluetooth security today.

— Kelly Jackson Higgins, Senior Editor, Dark Reading