high8.8
CVE-2021-4093
A flaw was found in the KVM's AMD code for supporting the Secure Encrypted Virtualization-Encrypted State (SEV-ES).
Impact
A flaw was found in the KVM's AMD code for supporting the Secure Encrypted Virtualization-Encrypted State (SEV-ES). A KVM guest using SEV-ES can trigger out-of-bounds reads and writes in the host kernel via a malicious VMGEXIT for a string I/O instruction (for example, outs or ins) using the exit reason SVM_EXIT_IOIO. This issue results in a crash of the entire system or a potential guest-to-host escape scenario.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Linux | Linux Kernel | from 5.11 before 5.14.16 |
| Redhat | Enterprise Linux | Version 8.0 |
| Fedoraproject | Fedora | Version 35 |
| Canonical | Ubuntu Linux | Versions 20.04, 21.10 |