Enlarge (credit: fuzecard.com)

The makers of the programmable Fuze smart card say it’s powerful enough to be your wallet in one card yet secure enough to be used the same way as traditional payment cards—including trusting it to restaurant servers when paying the bill. But it turns out that convenience comes with a major catch. A flaw makes it possible for anyone with even brief physical control of the card to surreptitiously siphon all data stored on the device.

Fuze representatives said they’re aware of the vulnerability and plan to fix it in an update scheduled for April 19. They also thanked the two researchers who, independent of one another, discovered the vulnerability and privately reported it. So far, however, Fuze officials have yet to fully inform users of the extent of the risk so they can prevent private data stored on the cards from being stolen or tampered with until the critical flaw is repaired.

Faulty assumptions

Mike Ryan, one of the two researchers, said he created attack code that impersonated the Android app that uses a Bluetooth connection to load credit card data onto the smart cards. While the official Fuze app takes care to prevent pairing with cards that have already been set up with another device, Ryan’s rogue app had no such restrictions. As a result, it allowed him to take complete control of a card, including reading, changing, or adding payment card numbers, expiration dates, and card-verification values.