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TI-2016-03418 Aliases CVE-2016-4020GHSA-vcqr-cc8h-57gj

The patch_instruction function in hw/i386/kvmvapic.c in QEMU does not initialize the…

Priority LOW 29Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · None · None
Fix status
Partial Red Hat: 11 fixed, 1 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.

Summary

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).

Why it matters now

EPSS 0.00372 31st percentileScored 2026-11-07
Fix Partial Red Hat: 3 advisoriesRed Hat: 11 fixed, 1 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 26

CPEVersionsRoleVendor
cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*up to 2.6.2VulnerableQEMU
cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*12.04VulnerableCanonical
cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*14.04VulnerableCanonical
cpe:2.3:o:canonical:ubuntu_linux:15.10:*:*:*:*:*:*:*15.10VulnerableCanonical
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*16.04VulnerableCanonical
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*8.0VulnerableDebian
cpe:2.3:a:redhat:openstack:6.0:*:*:*:*:*:*:*6.0VulnerableRed Hat
cpe:2.3:a:redhat:openstack:7.0:*:*:*:*:*:*:*7.0VulnerableRed Hat
cpe:2.3:a:redhat:openstack:8:*:*:*:*:*:*:*8VulnerableRed Hat
cpe:2.3:a:redhat:openstack:9:*:*:*:*:*:*:*9VulnerableRed Hat
  • cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:* Versions up to 2.6.2 Vulnerable ·QEMU
  • cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:* Versions 12.04 Vulnerable ·Canonical
  • cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:* Versions 14.04 Vulnerable ·Canonical
  • cpe:2.3:o:canonical:ubuntu_linux:15.10:*:*:*:*:*:*:* Versions 15.10 Vulnerable ·Canonical
  • cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* Versions 16.04 Vulnerable ·Canonical
  • cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Debian
  • cpe:2.3:a:redhat:openstack:6.0:*:*:*:*:*:*:* Versions 6.0 Vulnerable ·Red Hat
  • cpe:2.3:a:redhat:openstack:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
  • cpe:2.3:a:redhat:openstack:8:*:*:*:*:*:*:* Versions 8 Vulnerable ·Red Hat
  • cpe:2.3:a:redhat:openstack:9:*:*:*:*:*:*:* Versions 9 Vulnerable ·Red Hat
Show 16 more CPE
CPEVersionsRoleVendor
cpe:2.3:a:redhat:openstack:10:*:*:*:*:*:*:*10VulnerableRed Hat
cpe:2.3:a:redhat:openstack:11:*:*:*:*:*:*:*11VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*7.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_eus:7.4:*:*:*:*:*:*:*7.4VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_eus:7.5:*:*:*:*:*:*:*7.5VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_eus:7.6:*:*:*:*:*:*:*7.6VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_eus:7.7:*:*:*:*:*:*:*7.7VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*7.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:*7.4VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:*7.6VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.7:*:*:*:*:*:*:*7.7VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:*7.6VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_tus:7.7:*:*:*:*:*:*:*7.7VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*7.0VulnerableRed Hat
cpe:2.3:a:redhat:virtualization:4.0:*:*:*:*:*:*:*4.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*7.0Running onRed Hat
  • cpe:2.3:a:redhat:openstack:10:*:*:*:*:*:*:* Versions 10 Vulnerable ·Red Hat
  • cpe:2.3:a:redhat:openstack:11:*:*:*:*:*:*:* Versions 11 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_eus:7.4:*:*:*:*:*:*:* Versions 7.4 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_eus:7.5:*:*:*:*:*:*:* Versions 7.5 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_eus:7.6:*:*:*:*:*:*:* Versions 7.6 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_eus:7.7:*:*:*:*:*:*:* Versions 7.7 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:* Versions 7.4 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:* Versions 7.6 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_aus:7.7:*:*:*:*:*:*:* Versions 7.7 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:* Versions 7.6 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_tus:7.7:*:*:*:*:*:*:* Versions 7.7 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
  • cpe:2.3:a:redhat:virtualization:4.0:*:*:*:*:*:*:* Versions 4.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* Versions 7.0 Running on ·Red Hat

Remediation

Red Hat 3 advisories

  • RHSA-2017:2408 Released 2017-08-01 · Red Hat rating Moderate
    qemu-kvm-rhev security and bug fix update
    • Red Hat Enterprise Linux OpenStack Platform 6.0 (Juno) for RHEL 7 qemu-img-rhev-10:2.9.0-10.el7, qemu-kvm-common-rhev-10:2.9.0-10.el7, qemu-kvm-rhev-10:2.9.0-10.el7 +1
    • Red Hat Enterprise Linux OpenStack Platform 7.0 (Kilo) for RHEL 7 qemu-img-rhev-10:2.9.0-10.el7, qemu-kvm-common-rhev-10:2.9.0-10.el7, qemu-kvm-rhev-10:2.9.0-10.el7 +1
    • Red Hat OpenStack Platform 10.0 qemu-img-rhev-10:2.9.0-10.el7, qemu-kvm-common-rhev-10:2.9.0-10.el7, qemu-kvm-rhev-10:2.9.0-10.el7 +1
    • Red Hat OpenStack Platform 11.0 qemu-img-rhev-10:2.9.0-10.el7, qemu-kvm-common-rhev-10:2.9.0-10.el7, qemu-kvm-rhev-10:2.9.0-10.el7 +1
    • Red Hat OpenStack Platform 8.0 (Liberty) qemu-img-rhev-10:2.9.0-10.el7, qemu-kvm-common-rhev-10:2.9.0-10.el7, qemu-kvm-rhev-10:2.9.0-10.el7 +1
    • Red Hat OpenStack Platform 9.0 qemu-img-rhev-10:2.9.0-10.el7, qemu-kvm-common-rhev-10:2.9.0-10.el7, qemu-kvm-rhev-10:2.9.0-10.el7 +1
  • RHSA-2017:2392 Released 2017-08-01 · Red Hat rating Important
    qemu-kvm-rhev security, bug fix, and enhancement update
    • Red Hat Virtualization 4 Management Agent for RHEL 7 Hosts qemu-img-rhev-10:2.9.0-14.el7, qemu-kvm-common-rhev-10:2.9.0-14.el7, qemu-kvm-rhev-10:2.9.0-14.el7 +1
  • RHSA-2017:1856 Released 2017-08-01 · Red Hat rating Moderate
    qemu-kvm security, bug fix, and enhancement update
    • Red Hat Enterprise Linux Client (v. 7) qemu-img-10:1.5.3-141.el7, qemu-kvm-10:1.5.3-141.el7, qemu-kvm-common-10:1.5.3-141.el7 +1
    • Red Hat Enterprise Linux ComputeNode Optional (v. 7) qemu-img-10:1.5.3-141.el7, qemu-kvm-10:1.5.3-141.el7, qemu-kvm-common-10:1.5.3-141.el7 +1
    • Red Hat Enterprise Linux Server (v. 7) qemu-img-10:1.5.3-141.el7, qemu-kvm-10:1.5.3-141.el7, qemu-kvm-common-10:1.5.3-141.el7 +1
    • Red Hat Enterprise Linux Workstation (v. 7) qemu-img-10:1.5.3-141.el7, qemu-kvm-10:1.5.3-141.el7, qemu-kvm-common-10:1.5.3-141.el7 +1

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux OpenStack Platform 5 (Icehouse)AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux Client (v. 7)Fixed RHSA-2017:1856
Red Hat Enterprise Linux ComputeNode Optional (v. 7)Fixed RHSA-2017:1856
Red Hat Enterprise Linux OpenStack Platform 6.0 (Juno) for RHEL 7Fixed RHSA-2017:2408
Red Hat Enterprise Linux OpenStack Platform 7.0 (Kilo) for RHEL 7Fixed RHSA-2017:2408
Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2017:1856
Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2017:1856
Red Hat OpenStack Platform 10.0Fixed RHSA-2017:2408
Red Hat OpenStack Platform 11.0Fixed RHSA-2017:2408
Red Hat OpenStack Platform 8.0 (Liberty)Fixed RHSA-2017:2408
Red Hat OpenStack Platform 9.0Fixed RHSA-2017:2408
Red Hat Virtualization 4 Management Agent for RHEL 7 HostsFixed RHSA-2017:2392
Not affected: 3 products
  • Red Hat Enterprise Linux 5
  • Red Hat Enterprise Linux 6
  • Red Hat OpenStack Platform 12 (Pike)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2016-4020
  2. 2026-10-03 Alias added: GHSA-vcqr-cc8h-57gj

References

Patch 2

Advisory 7

Other 1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences