Spectre

Spectre, also known as Spectre-BHB or branch history injection (BHI), is a significant software vulnerability that was first exposed in 2018. This flaw in the design or implementation of CPU hardware utilizing speculative execution made computer memory an easy target for hackers. Attackers could exploit this vulnerability to inject malicious code and steal sensitive data, including usernames and passwords, by leveraging side-channel attacks such as timing attacks. The vulnerability proved to be a striking demonstration of the power of these types of attacks, despite not being a cryptographic attack in the traditional sense. The Spectre vulnerability has resurfaced with new hardware, AmpereOne, indicating its persistent threat to information security. A variant of the original Spectre v1 vulnerability, dubbed "GhostRace," exploits a race condition on a transiently executed path originating from a mis-speculated branch, similar to the original Spectre v1. This targets a racy code snippet or gadget that ultimately discloses information to the attacker. Any CPU hardware that uses speculative execution and is vulnerable to Spectre v1 is likely affected by this variant. The discovery of Spectre was initially reported to Intel in 2016 by Daniel Gruss, a researcher at Graz University of Technology, focusing on the prefetch side-channel at the center of Spectre. However, Intel did not immediately act on this report, which led to the widespread exposure of the vulnerability two years later. Gruss suggested that if Intel had taken their report more seriously and conducted thorough investigations on different machines, the Spectre vulnerability could have been identified and addressed much earlier.