4 What’s At Risk?
Spectre and Meltdown both take advantage of speculative execution mechanisms on a CPU. Put in other words, they’re hardware-based flaws and they exploit mechanisms and design decisions in computer hardware that were deliberate. Both exploits are extremely serious, and leave billions of devices at risk.
Meltdown, which affects Intel CPUs, could allow malicious programs to read kernel memory. That could allow attackers to access sensitive data like passwords, documents, photos and emails.
Spectre, which comprises two exploit techniques, breaks the isolation between different applications on a computer. While it’s a bit more difficult to pull off, Apple has said that it can be exploited via JavaScript in a web browser.