What are Meltdown and Spectre?
Meltdown and Spectre are hardware-level vulnerabilities discovered in 2018 that affect virtually all modern processors. They exploit a performance optimization technique called speculative execution to access data that should be protected.
How do they work?
Modern processors use speculative execution to predict and pre-execute instructions before knowing whether they will be needed. Meltdown and Spectre exploit this process to access memory that should be off-limits to user programs, potentially exposing passwords, encryption keys, and other sensitive data.
How are they mitigated?
Mitigations include operating system kernel patches (like KPTI for Meltdown), microcode updates from processor manufacturers, and application-level isolation techniques. These mitigations often come with some performance overhead.