bhyve, as used in FreeBSD through 12.1 and illumos (e.g., OmniOS CE through r151034 and OpenIndiana through Hipster 2020.04), does not properly restrict VMCS and VMCB read/write operations, as demonstrated by a root user in a container on an Intel system, who can gain privileges by modifying VMCS_HOST_RIP.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-24718
Reference (s):
- https://security.FreeBSD.org/advisories/FreeBSD-SA-20:28.bhyve_vmcs.asc
- https://security.netapp.com/advisory/ntap-20201016-0002/
- https://github.com/illumos/illumos-gate/blob/84971882a96ac0fecd538b02208054a872ff8af3/usr/src/uts/i86pc/io/vmm/intel/vmcs.c#L246-L249