Near Field Communication (NFC) has been used in mobile devices in some countries for a while and is now emerging on devices in use in the United States. This technology allows NFC enabled devices to communicate with each other within close range, typically a few centimeters. It is being rolled out as a way to make payments, by using the mobile device to communicate credit card information to an NFC enabled terminal. It is a new, cool, technology. But as with the introduction of any new technology, the question must be asked what kind of impact the inclusion of this new functionality has on the attack surface of mobile devices. In this paper, we explore this question by introducing NFC and its associated protocols.
Next we describe how to fuzz the NFC protocol stack for two devices as well as our results. Then we see for these devices what software is built on top of the NFC stack. It turns out that through NFC, using technologies like Android Beam or NDEF content sharing, one can make some phones parse images, videos, contacts, office documents, even open up web pages in the browser, all without user interaction. In some cases, it is even possible to completely take over control of the phone via NFC, including stealing photos, contacts, even sending text messages and making phone calls. So next time you present your phone to pay for your cab, be aware you might have just gotten owned.
Charlie Miller is Principal Research Consultant at Accuvant Labs. He was the first with a public remote exploit for both the iPhone and the G1 Android phone. He is a four time winner of the CanSecWest Pwn2Own competition. He has authored three information security books and holds a PhD from the University of Notre Dame. He is currently being held in a maximum security prison in Cupertino, but hopes to be released soon for good behavior.