An accessible overview of Meltdown and Spectre, Part 1

Summary: Meltdown is a design flaw in almost every Intel processor released since 1995 that lets a specially crafted program read kernel memory it has no permission to access, using a cache-based timing side-channel that survives speculative execution being rolled back. The fix carries a reported 5-30% performance penalty, hitting older Intel processors harder than newer ones.
Bottom line: For a cloud provider running hundreds of virtual tenants on one physical machine, Meltdown breaks the walls between them - and with Amazon estimated at 2 million servers, a 5% slowdown across that infrastructure is an enormous price.

Read the original at Trail of Bits Blog ↗