FORESHADOW: Extracting the Keys to the Intel SGX Kingdom with Transient Out-of-Order Execution

Speaker:
Marina Minkin, M.Sc. Thesis Seminar
Date:
Sunday, 11.11.2018, 17:30
Place:
Electrical Eng. Building 1061
Advisor:
Prof. Mark Silberstein

Trusted execution environments, and particularly the Software Guard eXtensions (SGX) included in recent Intel x86 processors, gained significant traction in recent years. A long track of research papers, and increasingly also real-world industry applications, take advantage of the strong hardware-enforced confidentiality and integrity guarantees provided by Intel SGX. Ultimately, enclaved execution holds the compelling potential of securely offloading sensitive computations to untrusted remote platforms. In this talk, I will present Foreshadow, a practical software-only microarchitectural attack that decisively dismantles the security objectives of current SGX implementations. Crucially, unlike previous SGX attacks, Foreshadow does not make any assumptions on the victim enclave’s code and does not necessarily require kernel-level access. At its core, Foreshadow abuses a speculative execution bug in modern Intel processors, on top of which we develop a novel exploitation methodology to reliably leak plaintext enclave secrets from the CPU cache. I will demonstrate Foreshadow practicality by extracting full cryptographic keys from Intel’s vetted architectural enclaves, and validate their correctness by launching rogue production enclaves and forging arbitrary local and remote attestation responses. The extracted remote attestation keys affect millions of devices. Joint Work with Jo Van Bulck, Ofir Weisse, Daniel Genkin, Baris Kasikci, Frank Piessens, Mark Silberstein, Thomas F. Wenisch, Yuval Yarom, and Raoul Strackx.

Back to the index of events