Spectre and Meltdown: How Modern CPUs Traded Security for Speed

For years, CPU designers focused on making processors faster. Techniques like out-of-order and speculative execution became standard to keep every part of the chip busy. These tricks helped achieve huge performance gains, but they also opened the door to a new kind of vulnerability.

In 2018, two major security flaws, Spectre and Meltdown, showed that the very features that made processors efficient could be used to steal private data from memory. These attacks broke some of the most fundamental assumptions about isolation between programs and the operating system.