take advantage of something known as a micro-op cache, which accelerates computation by storing basic commands and allowing the processor to retrieve them quickly and early in the speculative execution phase.
According to Venkat’s team, when a processor retrieves commands from the micro-op cache, the hackers could steal data. Since 2011, Intel computers use built-in micro-op caches. Venkat said, “Think about a hypothetical airport security scenario where TSA lets you in without checking your boarding pass because (1) it is fast and efficient, and (2) you will be checked for your boarding pass at the gate anyway”.
A computer processor also performs a similar function. It estimates that the check will pass, allowing instructions to enter the pipeline. Venkat explained, “Ultimately, if the prediction is incorrect, it will throw those instructions out of the pipeline, but this might be too late because those instructions could leave side-effects while waiting in the pipeline that an attacker could later exploit to infer secrets such as a password”.
All existing Spectre protections are ineffective against Venkat’s team’s latest attacks because they shield the processor at a later stage of speculative execution. The team found that two variants of the attacks can steal speculatively accessible data from Intel and AMD processors. Venkat explained the technical part. He said, “Intel’s suggested defense against…
