Are USB connections putting your data at risk?

Turns out, USB connections, the most common interface used globally to connect external devices to computers, make snooping easy.

University of Adelaide researchers found that USB connections are vulnerable to information 'leakage,' making them even less secure than has been thought.

The team tested more than 50 different computers and external USB hubs and found that over 90% of them leaked information to an external USB device.

"USB-connected devices include keyboards, cardswipers and fingerprint readers which often send sensitive information to the computer," said project leader Dr Yuval Yarom. "It has been thought that because that information is only sent along the direct communication path to the computer, it is protected from potentially compromised devices."

"But our research showed that if a malicious device or one that's been tampered with is plugged into adjacent ports on the same external or internal USB hub, this sensitive information can be captured. That means keystrokes showing passwords or other private information can be easily stolen," added Yarom.

Yarom noted that this "channel-to-channel crosstalk leakage" is analogous with water leaking from pipes. "Electricity flows like water along pipes - and it can leak out," he said. "In our project, we showed that voltage fluctuations of the USB port's data lines can be monitored from the adjacent ports on the USB hub."

Dr Yarom continued that the long-term solution is that USB connections should be redesigned to make them more secure.

The results are being presented at the USENIX Security Symposium in Vancouver, Canada.