Defeating UEFI’s SecureBoot

The Unified Extensible Firmware Interface (UEFI) is ment to replace the Basic Input/Output System (BIOS) firmware interface found on all IBM PC-compatible personal computers. But is it secure enough? Or, at least, more resilient than BIOS?

Corey Kallenberg, Security Researcher for the MITRE Corporation, and his colleagues Sam Cornwell, Xeno Kovah and John Butterworth have been testing ways to bypass UEFI’s SecureBoot – a new feature that enforces a signature check on the boot loader before the firmware transfers control to it.

In this podcast recorded at Hack In The Box Amsterdam 2014, Kallenberg explains how they have been able to circumvent that protection on roughly half of the computers that have it enabled, in order to install a malicious bootkit, and what this means for the future of UEFI.

Listen to the podcast here.


Corey Kallenberg (@coreykal) is a Security Researcher for The MITRE Corporation who has spent several years investigating operating system and firmware security on Intel computers.

In 2012, he co-authored work presented at DEF CON and IEEE S&P on using timing based attestation to detect Windows kernel hooks. In 2013, he helped discover critical problems with current implementations of the Trusted Computing Group’s “Static Root of Trust for Measurement”. Later, he discovered several vulnerabilities which allowed bypassing of “signed BIOS enforcement” on a number of systems, allowing an attacker to make malicious modifications to the platform firmware.