UBUNTU-CVE-2019-3887

Description

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.

CVSS Metrics

• v3.1•MEDIUM•Score: 5.6CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H
• v3.0•MEDIUM•Score: 5.6CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H

Affected Systems

• ubuntu•linux-azure

  < 4.18.0-1018.18~18.04.1

• ubuntu•linux-gcp-edge

  < 4.18.0-1011.12~18.04.1

• ubuntu•linux-hwe

  < 4.18.0-20.21~18.04.1

References (6)

• https://ubuntu.com/security/CVE-2019-3887
• https://www.openwall.com/lists/oss-security/2019/04/08/1
• https://ubuntu.com/security/notices/USN-3979-1
• https://ubuntu.com/security/notices/USN-3980-1
• https://ubuntu.com/security/notices/USN-3980-2
• https://www.cve.org/CVERecord?id=CVE-2019-3887