#HITB2014KUL White Paper: Using Intel TXT to Attack BIOSes


Authors: Xeno Kovah, Corey Kallenberg, John Butterworth amd Sam Cornwell - The MITRE Corporation

Presentation Overview: http://conference.hitb.org/hitbsecconf2014kul/sessions/senter-sandman-using-intel-txt-to-attack-bioses/


A comparatively large number of security problems at the PC BIOS level have been found in the last 2 years relative to the preceding years [7].

In this paper we will discuss the interplay between the behavior of Intel Trusted Execution Technology (TXT) and existing at- tacks, and how this leads to Intel TXT being useful for an attacker. We will also discuss how Intel TXT behavior has changed in “newer CPUs” (not defined by the Intel documentation), and how that removes the possibility of these initial attacks, while simultaneously removing the trustworthiness of technologies like Copernicus 2[8] for combatting attacks like the “Smite’em” SMM MitM[9]. This leads to a situation where if TXT behaves in the old way, a system is vulnerable to certain attacks, and if it behaves in the new way, it’s vulnerable to others.