Intel On Addressing New Research for Side-Channel Analysis

Like the other GPZ variants, Variant 4 uses speculative execution, a feature common to most modern processor architectures, to potentially expose certain kinds of data through a side channel. In this case, the researchers demonstrated Variant 4 in a language-based runtime environment. While we are not aware of a successful browser exploit, the most common use of runtimes, like JavaScript, is in web browsers.