Vulnerability in Qemu
CVE-2016-4020
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).
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (28.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 28.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Qemu
- Canonical Ubuntu Linux — versions 12.04, 14.04, 15.10
- Debian Linux — versions 8.0
- Red Hat Enterprise Linux — versions 7.0
- Red Hat Enterprise Linux Desktop — versions 7.0
- Red Hat Enterprise Linux Eus — versions 7.4, 7.5, 7.6
- Red Hat Enterprise Linux Server — versions 7.0
- Red Hat Enterprise Linux Server Aus — versions 7.4, 7.6, 7.7
- Red Hat Enterprise Linux Server Tus — versions 7.6, 7.7
- Red Hat Enterprise Linux Workstation — versions 7.0
References
- git.qemu.org/
- bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
- lists.gnu.org/archive/html/qemu-devel/2016-04/msg01106.html (mailing-list, Patch, Third Party Advisory)
- www.securityfocus.com/bid/86067 (VDB Entry, Third Party Advisory, vdb-entry)
- lists.gnu.org/archive/html/qemu-devel/2016-04/msg01118.html (mailing-list, Patch, Third Party Advisory)
- access.redhat.com/errata/RHSA-2017:2392 (vendor-advisory, Third Party Advisory)
- security.gentoo.org/glsa/201609-01 (vendor-advisory, Third Party Advisory)
- www.ubuntu.com/usn/USN-2974-1 (vendor-advisory, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2018/11/msg00038.html (mailing-list, Mailing List, Third Party Advisory)
- access.redhat.com/errata/RHSA-2017:2408 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2016-4020?
- CVE-2016-4020 is a medium-severity vulnerability in Qemu. CVSS score: 6.5/10. Published 2016-05-25.
- How severe is CVE-2016-4020?
- Medium severity. CVSS v3 base score is 6.5 out of 10.