CVE-2019-3887
Published: 9 April 2019
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.
From the Ubuntu Security Team
Marc Orr discovered that the KVM hypervisor implementation in the Linux kernel did not properly restrict APIC MSR register values when nested virtualization is used. An attacker in a guest vm could use this to cause a denial of service (host OS crash).
Notes
Author | Note |
---|---|
tyhicks | Ubuntu kernels do not enable nested KVM virtualization by default and are unaffected by this flaw in the default configuration. However, installing QEMU results in nested KVM support to be enabled via the /etc/modprobe.d/qemu-system-x86.conf file. To ensure that nested virtualization is not enabled, verify that the /sys/module/kvm_intel/parameters/nested file contains "N". |
Mitigation
If qemu is installed, to prevent nested virtualization from being enabled, set "options kvm_intel nested=0" in /etc/modprobe.d/qemu-system-x86.conf
Priority
Status
Package | Release | Status |
---|---|---|
linux-aws Launchpad, Ubuntu, Debian |
upstream |
Released
(5.1~rc4)
|
trusty |
Not vulnerable
(4.4.0-1002.2)
|
|
xenial |
Not vulnerable
(4.4.0-1001.10)
|
|
bionic |
Not vulnerable
(4.15.0-1001.1)
|
|
cosmic |
Released
(4.18.0-1016.18)
|
|
disco |
Released
(5.0.0-1006.6)
|
|
linux-azure Launchpad, Ubuntu, Debian |
trusty |
Not vulnerable
(4.15.0-1023.24~14.04.1)
|
bionic |
Released
(4.18.0-1018.18~18.04.1)
|
|
cosmic |
Released
(4.18.0-1018.18)
|
|
disco |
Released
(5.0.0-1006.6)
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Not vulnerable
(4.11.0-1009.9)
|
|
linux-gcp-edge Launchpad, Ubuntu, Debian |
upstream |
Released
(5.1~rc4)
|
trusty |
Does not exist
|
|
xenial |
Does not exist
|
|
bionic |
Released
(4.18.0-1011.12~18.04.1)
|
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
linux-aws-hwe Launchpad, Ubuntu, Debian |
upstream |
Released
(5.1~rc4)
|
trusty |
Does not exist
|
|
xenial |
Not vulnerable
(4.15.0-1030.31~16.04.1)
|
|
bionic |
Does not exist
|
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
linux Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(4.13.0-16.19)
|
cosmic |
Released
(4.18.0-20.21)
|
|
disco |
Released
(5.0.0-15.16)
|
|
trusty |
Not vulnerable
(3.11.0-12.19)
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Not vulnerable
(4.2.0-16.19)
|
|
Patches: Introduced by 15303ba5d1cd9b28d03a980456c0978c0ea3b208 Introduced by c992384bde84fb2f0318bdb4f6c710605dd7a217 |
||
linux-azure-edge Launchpad, Ubuntu, Debian |
bionic |
Released
(4.18.0-1018.18~18.04.1)
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Not vulnerable
(4.11.0-1009.9)
|
|
linux-euclid Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Not vulnerable
(4.4.0-9019.20)
|
|
linux-flo Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [abandoned])
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Ignored
(abandoned)
|
|
linux-gcp Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(4.15.0-1001.1)
|
cosmic |
Released
(4.18.0-1011.12)
|
|
disco |
Released
(5.0.0-1006.6)
|
|
trusty |
Does not exist
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Not vulnerable
(4.10.0-1004.4)
|
|
linux-gke Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Ignored
(end of standard support)
|
|
linux-goldfish Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [abandoned])
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Ignored
(end of life)
|
|
linux-grouper Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [abandoned])
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Does not exist
|
|
linux-hwe Launchpad, Ubuntu, Debian |
bionic |
Released
(4.18.0-20.21~18.04.1)
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Not vulnerable
(4.8.0-36.36~16.04.1)
|
|
linux-hwe-edge Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(5.0.0-15.16~18.04.1)
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Not vulnerable
(4.8.0-36.36~16.04.1)
|
|
linux-kvm Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(4.15.0-1002.2)
|
cosmic |
Released
(4.18.0-1012.12)
|
|
disco |
Released
(5.0.0-1006.6)
|
|
trusty |
Does not exist
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Not vulnerable
(4.4.0-1004.9)
|
|
linux-lts-trusty Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Does not exist
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Does not exist
|
|
linux-lts-utopic Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Ignored
(end of life, was ignored)
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Does not exist
|
|
linux-lts-vivid Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Ignored
(end of life, was ignored)
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Does not exist
|
|
linux-lts-wily Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Ignored
(end of life, was ignored)
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Does not exist
|
|
linux-lts-xenial Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Not vulnerable
(4.4.0-13.29~14.04.1)
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Does not exist
|
|
linux-maguro Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [abandoned])
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Does not exist
|
|
linux-mako Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [abandoned])
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Ignored
(abandoned)
|
|
linux-manta Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
cosmic |
Does not exist
|
|
disco |
Does not exist
|
|
trusty |
Does not exist
(trusty was ignored [abandoned])
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Does not exist
|
|
linux-oem Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(4.15.0-1002.3)
|
cosmic |
Not vulnerable
(4.15.0-1004.5)
|
|
disco |
Not vulnerable
(4.15.0-1021.24)
|
|
trusty |
Does not exist
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Ignored
(end of standard support, was needs-triage)
|
|
linux-oracle Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(4.15.0-1007.9)
|
cosmic |
Not vulnerable
(4.15.0-1007.9)
|
|
disco |
Not vulnerable
(4.15.0-1007.9)
|
|
trusty |
Does not exist
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Not vulnerable
(4.15.0-1007.9~16.04.1)
|
|
linux-raspi2 Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(4.13.0-1005.5)
|
cosmic |
Released
(4.18.0-1014.16)
|
|
disco |
Released
(5.0.0-1008.8)
|
|
trusty |
Does not exist
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Not vulnerable
(4.2.0-1013.19)
|
|
linux-snapdragon Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(4.4.0-1077.82)
|
cosmic |
Does not exist
|
|
disco |
Released
(5.0.0-1012.12)
|
|
trusty |
Does not exist
|
|
upstream |
Released
(5.1~rc4)
|
|
xenial |
Not vulnerable
(4.4.0-1012.12)
|
Severity score breakdown
Parameter | Value |
---|---|
Base score | 5.6 |
Attack vector | Local |
Attack complexity | High |
Privileges required | Low |
User interaction | None |
Scope | Changed |
Confidentiality | None |
Integrity impact | None |
Availability impact | High |
Vector | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H |