Jul 13, 2022
Security researchers have uncovered yet another vulnerability affecting numerous older AMD and Intel microprocessors that could bypass current defenses and result in Spectre-based speculative-execution attacks. Dubbed Retbleed by ETH Zurich researchers Johannes Wikner and Kaveh Razavi, the issue is tracked as CVE-2022-29900 (AMD) and CVE-2022-29901 (Intel), with the chipmakers releasing software mitigations as part of a coordinated disclosure process. Retbleed is also the latest addition to a class of Spectre attacks known as Spectre-BTI (CVE-2017-5715 or Spectre-V2), which exploit the side effects of an optimization technique called speculative execution by means of a timing side channel to trick a program into accessing arbitrary locations in its memory space and leak private information. Speculative execution attempts to fill the instruction pipeline of a program by predicting which instruction will be executed next in order to gain a performance boost, while also u