AMD’s Secure Encrypted Virtualization (SEV) technology could allow attackers to recover plaintext memory data from guest VMs protected by AMD’s technology. The page-fault side channel attack, dubbed SEVered, takes advantage of lack in the integrity protection of the page-wise encryption of the main memory, allowing a malicious hypervisor to extract the full content in plaintext from SEV-encrypted VMs. The research was carried out by four Fraunhofer Institute for Applied and Integrated Security in Munich.
Source: https://thehackernews.com/2018/05/amd-sev-encryption.html

