Speculative execution attacks are rarely mitigated by disabling simultaneous multi-threading (which Intel brands as hyper-threading). Some of these attacks target one and some target the other. Also note that Data Bounce actually affects all Intel CPUs going back to 2004 (when speculative execution was introduced) not 2011 (when SMT was introduced).<br><br>ZombieLoad is an SMT attack. Disabling Hyper-threading should mitigate. The JavaScript proof of concept makes it a fairly big concern for typical users.<br><br>RIDL is a speculative execution vulnerability (actually it just attacks hardware primitives needed for speculation, not speculation itself). Attacks do not need SMT but do benefit from it. So, turning off SMT can help, but does not make you fully safe. This also has a JavaScript proof of concept, but one that is a bit less concerning due to a very low bit rate and the fact that the researchers ended up resorting to an out-of-browser demonstration platform.<br><br>Fallout is a speculative execution vulnerability (actually it just attacks hardware primitives needed for speculation, not speculation itself, similar to RIDL). This attack does not work across SMT threads, only threads that share a logical processor, so disabling hyper-threading would have no impact. For the average user however, this is probably less of a concern than either of the previous. However, it should be a major concern for cloud operators and to a lesser extent cloud computing customers.<br><br>Store-to-Leak Forwarding is a paper that describes 3 new related vulnerabilities. They are all very similar to parts of RIDL.<br><br>Data Bounce is a speculative execution vulnerability which on it's own is a somewhat minor problem (breaks ASLR and KASLR which is only useful in combination with other vulnerabilities). It has nothing to do with SMT so cannot be mitigated by disabling hyper-threading.<br><br>Fetch+Bounce is mechanically identical to Data Bounce run 3 times, with some extra measurement and data processing. Like Data Bounce, it has nothing to do with SMT. This allows an attacker to see what parts of the kernel are being executed.<br><br>Speculative Fetch+Bounce is a final refinement on the other 2 attacks in the Store-to-Leak Forwarding paper and is basically a slightly different derivation of RIDL. Mechanically it is Fetch+Bounce plus more data processing so it is not mitigated by disabling SMT.,(reply>), @flameshana9 Some times I sort of suck at simplifying. Lets try again.<br><br><br>5 Vulnerabilities were announced<br><br><br>The scariest one for normal users can be protected against by turning off hyper threading.<br><br><br><br>The rest can be protected from by upgrading to AMD. Although 1 can be made slightly less scary by turning off hyper threading.<br><br><br>If you are a cloud person, all but one of them are really scary. And, that one is still pretty scary. There is no good news here for you. <br><br>Also LTT got 2 different optimizations confused thus oversimplifying the situation. 4 of these target one (Speculative execution) which has been in Intel CPUs since 2004. The other targets Hyper-threading which has been in Intel CPUs since 2011.,(reply>), That's cool and all, but why not help out in fixing it? Most people here won't understand 10 words of that.