JTAG Fault Injection Attack

Fault injection attacks are wide spread in the domain of smart cards and microcontrollers but have not been yet democratized on complex embedded microprocessors, such as system on chip that can be found in smart phones, tablets, and automotive systems. The main explanation is the difficulty involved in injecting a fault at the right place and at the right time to make these attacks effective on such devices. However, for development and debugging, these devices provide new tools that could be considered as possibly enabling attacks. One of them, the JTAG debug tool is present on most electronic devices today. In this letter, we present the first fault injection attack based on JTAG. Using the example of a privilege escalation attack, we detail how this tool can be used either to check the feasibility of this attack by fault injection or to perform an actual attack.