The new Linux kernel security update comes one and a half months after the previous update and it’s available for the Ubuntu 21.04 (Hirsute Hippo), Ubuntu 20.04 LTS (Focal Fossa), and Ubuntu 18.04 LTS (Bionic Beaver) operating systems series.
Patched in these kernel updates are several security vulnerabilities affecting the KVM hypervisor for AMD processors on all Ubuntu releases. These include CVE-2021-3656 and CVE-2021-3653, both flaws allowing an attacker in a guest virtual machine to read or write to portions of the host’s physical memory, as well as CVE-2021-22543, a use-after-free vulnerability that could allow an attacker who could start and control a virtual machine to expose sensitive information or execute arbitrary code. These issues were discovered and reported by Maxim Levitsky and Paolo Bonzini. Learn more here.