Medium severity6.5NVD Advisory· Published May 25, 2016· Updated Jun 17, 2026

CVE-2016-4020

Description

The patch_instruction function in hw/i386/kvmvapic.c in QEMU does not initialize the imm32 variable, which allows local guest OS administrators to obtain sensitive information from host stack memory by accessing the Task Priority Register (TPR).

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected products

QEMU/Qemu2 versions
cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*range: <=2.6.2
- (no CPE)
Red Hat/Openstack6 versions
cpe:2.3:a:redhat:openstack:10:*:*:*:*:*:*:*+ 5 more
- cpe:2.3:a:redhat:openstack:10:*:*:*:*:*:*:*
- cpe:2.3:a:redhat:openstack:11:*:*:*:*:*:*:*
- cpe:2.3:a:redhat:openstack:6.0:*:*:*:*:*:*:*
- cpe:2.3:a:redhat:openstack:7.0:*:*:*:*:*:*:*
- cpe:2.3:a:redhat:openstack:8:*:*:*:*:*:*:*
- cpe:2.3:a:redhat:openstack:9:*:*:*:*:*:*:*
Red Hat/Virtualization
cpe:2.3:a:redhat:virtualization:4.0:*:*:*:*:*:*:*
Canonical/Ubuntu Linux4 versions
cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*+ 3 more
- cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:15.10:*:*:*:*:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
Debian/linux
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
Red Hat/Enterprise Linux Desktop
cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
Red Hat/Enterprise Linux Eus4 versions
cpe:2.3:o:redhat:enterprise_linux_eus:7.4:*:*:*:*:*:*:*+ 3 more
- cpe:2.3:o:redhat:enterprise_linux_eus:7.4:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_eus:7.5:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_eus:7.6:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_eus:7.7:*:*:*:*:*:*:*
Red Hat/Enterprise Linux Server
cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
Red Hat/Enterprise Linux Server Aus3 versions
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:*+ 2 more
- cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_aus:7.7:*:*:*:*:*:*:*
Red Hat/Enterprise Linux Server Tus2 versions
cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_tus:7.7:*:*:*:*:*:*:*
Red Hat/Enterprise Linux Workstation
cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
osv-coords21 versions
pkg:rpm/opensuse/qemu&distro=openSUSE%20Tumbleweed pkg:rpm/opensuse/qemu-linux-user&distro=openSUSE%20Tumbleweed pkg:rpm/suse/kvm&distro=SUSE%20Linux%20Enterprise%20Server%2011%20SP3-LTSS pkg:rpm/suse/kvm&distro=SUSE%20Linux%20Enterprise%20Server%2011%20SP3-TERADATA pkg:rpm/suse/kvm&distro=SUSE%20Linux%20Enterprise%20Server%2011%20SP4 pkg:rpm/suse/kvm&distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2011%20SP4 pkg:rpm/suse/qemu&distro=SUSE%20Linux%20Enterprise%20Desktop%2012 pkg:rpm/suse/qemu&distro=SUSE%20Linux%20Enterprise%20Desktop%2012%20SP1 pkg:rpm/suse/qemu&distro=SUSE%20Linux%20Enterprise%20Server%2012 pkg:rpm/suse/qemu&distro=SUSE%20Linux%20Enterprise%20Server%2012%20SP1 pkg:rpm/suse/qemu&distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2012 pkg:rpm/suse/qemu&distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2012%20SP1 pkg:rpm/suse/xen&distro=SUSE%20Linux%20Enterprise%20Desktop%2012%20SP1 pkg:rpm/suse/xen&distro=SUSE%20Linux%20Enterprise%20Server%2011%20SP4 pkg:rpm/suse/xen&distro=SUSE%20Linux%20Enterprise%20Server%2012%20SP1 pkg:rpm/suse/xen&distro=SUSE%20Linux%20Enterprise%20Server%2012-LTSS pkg:rpm/suse/xen&distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2011%20SP4 pkg:rpm/suse/xen&distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2012 pkg:rpm/suse/xen&distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2012%20SP1 pkg:rpm/suse/xen&distro=SUSE%20Linux%20Enterprise%20Software%20Development%20Kit%2011%20SP4 pkg:rpm/suse/xen&distro=SUSE%20Linux%20Enterprise%20Software%20Development%20Kit%2012%20SP1
< 2.6.1-1.5+ 20 more
- (no CPE)range: < 2.6.1-1.5
- (no CPE)range: < 2.6.1-1.5
- (no CPE)range: < 1.4.2-46.1
- (no CPE)range: < 1.4.2-46.1
- (no CPE)range: < 1.4.2-44.1
- (no CPE)range: < 1.4.2-44.1
- (no CPE)range: < 2.0.2-48.19.1
- (no CPE)range: < 2.3.1-14.1
- (no CPE)range: < 2.0.2-48.19.1
- (no CPE)range: < 2.3.1-14.1
- (no CPE)range: < 2.0.2-48.19.1
- (no CPE)range: < 2.3.1-14.1
- (no CPE)range: < 4.5.3_08-17.1
- (no CPE)range: < 4.4.4_07-37.1
- (no CPE)range: < 4.5.3_08-17.1
- (no CPE)range: < 4.4.4_04-22.22.2
- (no CPE)range: < 4.4.4_07-37.1
- (no CPE)range: < 4.4.4_04-22.22.2
- (no CPE)range: < 4.5.3_08-17.1
- (no CPE)range: < 4.4.4_07-37.1
- (no CPE)range: < 4.5.3_08-17.1

Patches

Vulnerability mechanics

References

lists.gnu.org/archive/html/qemu-devel/2016-04/msg01106.htmlnvdPatchThird Party Advisory
lists.gnu.org/archive/html/qemu-devel/2016-04/msg01118.htmlnvdPatchThird Party Advisory
www.securityfocus.com/bid/86067nvdThird Party AdvisoryVDB Entry
www.ubuntu.com/usn/USN-2974-1nvdThird Party Advisory
access.redhat.com/errata/RHSA-2017:1856nvdThird Party Advisory
access.redhat.com/errata/RHSA-2017:2392nvdThird Party Advisory
access.redhat.com/errata/RHSA-2017:2408nvdThird Party Advisory
bugzilla.redhat.com/show_bug.cginvdIssue TrackingThird Party Advisory
lists.debian.org/debian-lts-announce/2018/11/msg00038.htmlnvdMailing ListThird Party Advisory
security.gentoo.org/glsa/201609-01nvdThird Party Advisory
git.qemu.orgnvd

News mentions

No linked articles in our index yet.

cvss	0.423
epss	0.000
exploit	0.000
kev	0.000
patch	0.000
ransomware	0.000