CVE-2016-9921

Name: CVE-2016-9921
Creator: NVD / NIST
Published: 2016-12-23T22:59:00.55+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.39%

Last modified Jun 17, 2026

CVE-2016-9921 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Quick emulator (Qemu) built with the Cirrus CLGD 54xx VGA Emulator support is vulnerable to a divide by zero issue. It could occur while copying VGA data when cirrus graphics mode was set to be VGA. EPSS estimates a 0.39% chance of exploitation in the next 30 days.

Description

Quick emulator (Qemu) built with the Cirrus CLGD 54xx VGA Emulator support is vulnerable to a divide by zero issue. It could occur while copying VGA data when cirrus graphics mode was set to be VGA. A privileged user inside guest could use this flaw to crash the Qemu process instance on the host, resulting in DoS.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.39%

31.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-369

Affected Software

Vendor	Product	Versions	Update
Qemu	Qemu	<= 2.7.1	—
Qemu	Qemu	2.8.0	Rc0
Debian	Debian Linux	8.0	—
Redhat	Openstack	6.0	—
Redhat	Openstack	7.0	—
Redhat	Openstack	8	—
Redhat	Openstack	9	—
Redhat	Openstack	10	—
Redhat	Openstack	11	—
Redhat	Virtualization	4.0	—

References

http://www.openwall.com/lists/oss-security/2016/12/09/1Mailing List, Patch, Third Party Advisory
http://www.securityfocus.com/bid/94803Third Party Advisory, VDB Entry
https://access.redhat.com/errata/RHSA-2017:2392Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:2408Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/09/msg00007.htmlMailing List, Third Party Advisory
https://security.gentoo.org/glsa/201701-49Third Party Advisory
http://www.openwall.com/lists/oss-security/2016/12/09/1Mailing List, Patch, Third Party Advisory
http://www.securityfocus.com/bid/94803Third Party Advisory, VDB Entry
https://access.redhat.com/errata/RHSA-2017:2392Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:2408Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/09/msg00007.htmlMailing List, Third Party Advisory
https://security.gentoo.org/glsa/201701-49Third Party Advisory

Timeline

Published: Dec 23, 2016
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2016-9921?

How severe is CVE-2016-9921?

CVE-2016-9921 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.39% probability of exploitation in the next 30 days.

How do I fix CVE-2016-9921?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2016-9921?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST