Speculative Dereferencing of Registers: Reviving Foreshadow [pdf]
The article&#x27;s presentation of the research is completely wrong. There aren&#x27;t any new side channels here. All the paper purports to show (albeit in a somewhat self-aggrandizing manner) is that the mechanisms for Meltdown and Foreshadow were incompletely understood when <i>originally</i> <i>presented</i>. But there&#x27;s nothing knew in the notion that speculative execution optimizations are responsible for most side channels, nor that they played a role in Meltdown and Foreshadow. &quot;Spectre&quot; is a play on words--it alludes to speculative execution.<p>There aren&#x27;t any major new exploits detailed in this paper. They introduce a slightly new gadget for exposing data, but it can be and is mitigated by existing techniques (e.g. retpolines). The only noteworthy aspect is that, as it regards SGX, the mitigations haven&#x27;t yet been generally applied. But new ways to break SGX are a dime a dozen these days.<p>Interesting and rigorous work, but there don&#x27;t seem to be any real implications here. It&#x27;s more like a more concise restatement of researchers&#x27; present understanding, using the benefit of hindsight and some additional footwork to fill in some small gaps.