CVE-2016-4020

MEDIUM

QEMU - Info Disclosure

Title source: llm

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).

References (11)

[Patch] http://git.qemu.org/?p=qemu.git%3Ba=commit%3Bh=691a02e2ce0c413236a78dee6f2651c937b09fb0

[Third Party Advisory, VDB Entry] http://www.securityfocus.com/bid/86067

[Third Party Advisory] http://www.ubuntu.com/usn/USN-2974-1

[Third Party Advisory] https://access.redhat.com/errata/RHSA-2017:1856

[Third Party Advisory] https://access.redhat.com/errata/RHSA-2017:2392

[Third Party Advisory] https://access.redhat.com/errata/RHSA-2017:2408

[Issue Tracking, Third Party Advisory] https://bugzilla.redhat.com/show_bug.cgi?id=1313686

[Mailing List, Third Party Advisory] https://lists.debian.org/debian-lts-announce/2018/11/msg00038.html

[Patch, Third Party Advisory] https://lists.gnu.org/archive/html/qemu-devel/2016-04/msg01106.html

[Patch, Third Party Advisory] https://lists.gnu.org/archive/html/qemu-devel/2016-04/msg01118.html

[Third Party Advisory] https://security.gentoo.org/glsa/201609-01

Scores

CVSS v3 6.5

EPSS 0.0008

EPSS Percentile 24.5%

Attack Vector LOCAL

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

Classification

Status draft

Affected Products (25)

qemu/qemu < 2.6.2

canonical/ubuntu_linux

debian/debian_linux

redhat/openstack

redhat/enterprise_linux_desktop

redhat/enterprise_linux_eus

... and 10 more

Timeline

Published May 25, 2016

Tracked Since Feb 18, 2026