UC San Diego Computer Science and Engineering Professor Dean Tullsen and his Ph.D. student Mohammadkazem Taram teamed up with University of Virginia (UVA) School of Engineering computer science researchers to uncover a line of attack that breaks current Spectre defenses. This means that billions of computers and other devices across the globe are just as vulnerable today as they were when Spectre was first announced.
The team reported its discovery to international chip makers in April and will present the new challenge at a worldwide computing architecture conference, the International Symposium on Computer Architecture, or ISCA, in June.
Led by Ashish Venkat, William Wulf Career Enhancement Assistant Professor of Computer Science at UVA Engineering and a UC San Diego CSE alumnus, and CSE’s Tullsen, the researchers, including Venkat’s Ph.D. students Logan Moody and lead student author Xida Ren, found a new way for hackers to exploit something called a “micro-op cache,” which speeds up computing by storing simple commands and allowing the processor to fetch them quickly and early in the speculative execution process. Micro-op caches have been built into Intel computers manufactured since 2011.
The UC San Diego/UVA team reverse-engineered certain undocumented features in Intel and AMD processors. They have detailed the findings in their paper: “I See Dead µops: Leaking Secrets via Intel/AMD Micro-Op Caches”
These UC San Diego and UVA teams have collaborated before, including on a paper Taram presented at the ACM International Conference on Architectural Support for Programming Languages and Operating Systems in April 2019. The paper, “Context-Sensitive Fencing: Securing Speculative Execution via Microcode Customization,” which introduced one of just a handful more targeted microcode-based defenses developed to stop Spectre in its tracks, was recently selected as a Top Pick in Hardware and Embedded Security among papers published in the six-year period between 2014 and 2019.
Read the full story from UVA about their research and its impact here.