Evan Vuckovic

What is Speculative Execution?

Speculative Execution is a procedure used by CPUs to optimize computing performance by carrying out multiple tasks at once. With speculative execution, the CPU can then better serve users by predicting the path that has the highest probability of being taken, and then ‘prefetch’ that information. When a CPU predicts the incorrect path, then the prefetched results are pushed to an unsecured portion of its cache memory.

What is Meltdown?

Meltdown is security threat that exploits “rogue data cache load” which allows potential bad actors to access kernel memory. The Meltdown exploitation is formally known as CVE-2017-5754.

What is Spectre?

Spectre is a security threat for two different points of exploitation know as “bounds check bypass” and “branch target injection.” These two vulnerabilities are formally named CVE-2017-5753 and CVE-2017-5715, and are collectively known as Spectre. This process takes advantage of the lag in time a busy CPU takes to verify memory access. Same as Meltdown, Spectre is too vulnerable to kernel memory leaks.