An adversary leverages a firmware weakness within the Thunderbolt protocol, on a computing device to manipulate Thunderbolt controller firmware in order to exploit vulnerabilities in the implementation of authorization and verification schemes within Thunderbolt protection mechanisms. Upon gaining physical access to a target device, the adversary conducts high-level firmware manipulation of the victim Thunderbolt controller SPI (Serial Peripheral Interface) flash, through the use of a SPI Programing device and an external Thunderbolt device, typically as the target device is booting up. If successful, this allows the adversary to modify memory, subvert authentication mechanisms, spoof identities and content, and extract data and memory from the target device. Currently 7 major vulnerabilities exist within Thunderbolt protocol with 9 attack vectors as noted in the Execution Flow.

Not present

1. The adversary needs at least a few minutes of physical access to a system with an open Thunderbolt port, version 3 or lower, and an external thunderbolt device controlled by the adversary with maliciously crafted software and firmware, via an SPI Programming device, to exploit weaknesses in security protections.

1. SPI Programming device capable of modifying/configuring or replacing the firmware of Thunderbolt device stored on SPI Flash of target Thunderbolt controller, as well as modification/spoofing of adversary-controlled Thunderbolt controller.
2. Precrafted scripts/tools capable of implementing the modification and replacement of Thunderbolt Firmware.
3. Thunderbolt-enabled computing device capable of interfacing with target Thunderbolt device and extracting/dumping data and memory contents of target device.

1. An adversary steals a password protected laptop that contains a Thunderbolt 3 enabled port, from a work environment. The adversary uses a screw driver to remove the back panel of the laptop and connects a SPI Programming device to the Thunderbolt Host Controller SPI Flash of the stolen victim device to interface with it on the adversary's own Thunderbolt enabled device via Thunderbolt cables. The SPI Programming device is utilized to execute scripts/tools from the adversary's own system to copy, parse, and modify the victim's Thunderbolt firmware stored on SPI Flash. The device UUID value is obtained, by computing the appropriate offset based upon Thunderbolt firmware version and the OS of victim device, from the DROM section of victim Thunderbolt host controller firmware image. The firmware image is written to adversary Thunderbolt host controller SPI flash to clone and spoof victim device identity. The adversary reboots the victim device, with the victim device identifying the Thunderbolt connection of the adversary's Thunderbolt device as itself and enables PCIe tunneling. The adversary finally transfers the hard drive and memory contents of victim device across Thunderbolt connection.