ToorCon TwentyOne speaker: Ang Cui

Dr. Ang Cui is the Founder and Chief Scientist of Red Balloon Security. Dr. Cui received his PhD from Columbia University in 2015. His doctoral dissertation, titled ”Embedded System Security: A Software-based Approach”, focused exclusively on scientific inquiries concerning the exploitation and defense embedded systems. Ang has focused on developing new technologies to defend embedded systems against exploitation. During the course of his research, he has uncovered a number of serious vulnerabilities within ubiquitous embedded devices like Cisco routers, HP printers and Cisco IP phones. Dr. Cui is also the author of FRAK and the inventor of Software Symbiote technology. Ang has received various awards on his work on reverse engineering commercial devices and is also the recipient of the Symantec Graduate Fellowship and was selected as a DARPA Riser in 2015.


Talks

100 Seconds of Solitude: Defeating Cisco Trust Anchor With FPGA Bitstream Shenanigans

First commercially introduced in 2013, Cisco Trust Anchor module(TAm) is a proprietary hardware security module that is used in a wide range of Cisco products, including enterprise routers, switches and firewalls. TAm is the foundational root of trust that underpins all other Cisco security and trustworthy computing mechanisms in such devices. We disclose two 0-day vulnerabilities and show a remotely exploitable attack chain that reliably bypasses Cisco Trust Anchor. We present an in-depth analysis of the TAm, from both theoretical and applied perspectives. We present a series of architectural and practical flaws of TAm, describe theoretical methods of attack against such flaws. Next, we enumerate limitations in current state-of-the-art offensive capabilities that made the design of TAm seem secure. Using Cisco 1001-X series of Trust Anchor enabled routers as a demonstrative platform, we present a detailed analysis of a current implementation of TAm, including results obtained through hardware reverse engineering, Trust Anchor FPGA bitstream analysis, and the reverse engineering of numerous Cisco trustworthy computing mechanisms that depend on TAm. Finally, we present two 0-day vulnerabilities within Cisco IOS and TAm and demonstrate a remotely exploitable attack chain that results in persistent compromise of an up-to-date Cisco router. We discuss the implementation of our TAm bypass, which involves novel methods of reliably manipulating FPGA functionality through bitstream analysis and modification while circumventing the need to perform RTL reconstruction. The use of our methods of manipulation creates numerous possibilities in the exploitation of embedded systems that use FPGAs. While this presentation focuses on the use of our FPGA manipulation techniques in the context of Cisco Trust Anchor, we briefly discuss other uses of our bitstream modification techniques.

Hot Tub Island

Take a boat out to Hot Tub Island! Just meet at the dock next to the event venue to catch a ride out.