Vulnerability 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).
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Qemu | Qemu | <= 2.6.2 |
| Canonical | Ubuntu Linux | 12.04 |
| Debian | Debian Linux | 8.0 |
| Redhat | Openstack | 6.0 |
| Redhat | Enterprise Linux Desktop | 7.0 |
| Redhat | Enterprise Linux Eus | 7.4 |
| Redhat | Enterprise Linux Server | 7.0 |
| Redhat | Enterprise Linux Server Aus | 7.4 |
| Redhat | Enterprise Linux Server Tus | 7.6 |
| Redhat | Enterprise Linux Workstation | 7.0 |
| Redhat | Virtualization | 4.0 |
| Redhat | Enterprise Linux | 7.0 |
References
- http://git.qemu.org/?p=qemu.git%3Ba=commit%3Bh=691a02e2ce0c413236a78dee6f2651c93
- http://www.securityfocus.com/bid/86067Third Party AdvisoryVDB Entry
- http://www.ubuntu.com/usn/USN-2974-1Third Party Advisory
- https://access.redhat.com/errata/RHSA-2017:1856Third Party Advisory
- https://access.redhat.com/errata/RHSA-2017:2392Third Party Advisory
- https://access.redhat.com/errata/RHSA-2017:2408Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1313686Issue TrackingThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2018/11/msg00038.htmlMailing ListThird Party Advisory
- https://lists.gnu.org/archive/html/qemu-devel/2016-04/msg01106.htmlPatchThird Party Advisory
- https://lists.gnu.org/archive/html/qemu-devel/2016-04/msg01118.htmlPatchThird Party Advisory
- https://security.gentoo.org/glsa/201609-01Third Party Advisory
- http://git.qemu.org/?p=qemu.git%3Ba=commit%3Bh=691a02e2ce0c413236a78dee6f2651c93
- http://www.securityfocus.com/bid/86067Third Party AdvisoryVDB Entry
- http://www.ubuntu.com/usn/USN-2974-1Third Party Advisory
- https://access.redhat.com/errata/RHSA-2017:1856Third Party Advisory
FAQ
What is CVE-2016-4020?
CVE-2016-4020 is a vulnerability with a CVSS score of 6.5 (MEDIUM). 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 b...
How severe is CVE-2016-4020?
CVE-2016-4020 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2016-4020?
Check the references section above for vendor advisories and patch information. Affected products include: Qemu Qemu, Canonical Ubuntu Linux, Debian Debian Linux, Redhat Openstack, Redhat Enterprise Linux Desktop.