Theoretical explanation The Intel Optimization Reference Manual says the following regarding

Posted by Jann Horn, Project Zero We have discovered that CPU data cache timing can be abused to efficiently leak information out of misspeculated execution, leading to (at worst) arbitrary virtual memory read vulnerabilities across local security boundaries in various contexts. Variants of this issue are known to affect many modern processors, including certain processors by Intel, AMD and ARM. For a few Intel and AMD CPU models, we have exploits that work against real software. We reported this issue to Intel, AMD and ARM on 2017-06-01 [1]. So far, there are three known variants of the issue: Variant 1: bounds check bypass (CVE-2017-5753) Variant 2: branch target injection (CVE-2017-5715) Variant 3: rogue data cache load (CVE-2017-5754)