A flaw was found in the way KVM hypervisor handled x2APIC Machine Specific Rregister (MSR) access with nested(=1) virtualization enabled. In that, L1 guest could access L0's APIC register values via L2 guest, when 'virtualize x2APIC mode' is enabled. A guest could use this flaw to potentially crash the host kernel resulting in DoS issue. Kernel versions from 4.16 and newer are vulnerable to this issue.

References[email protected]


Source: MITRE

Published: 2019-04-09

Updated: 2019-05-21

Type: CWE-20

Risk Information

CVSS v2.0

Base Score: 4.7

Vector: AV:L/AC:M/Au:N/C:N/I:N/A:C

Impact Score: 6.9

Exploitability Score: 3.4

Severity: MEDIUM

CVSS v3.0

Base Score: 5.6

Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H

Impact Score: 4

Exploitability Score: 1.1

Severity: MEDIUM