CVE-2016-9921: debian debian_linux Divide By Zero
Vulnerability summary
CVE-2016-9921 is a medium (CVSS 6.5) Divide By Zero vulnerability in debian debian_linux. EPSS estimates a 0.41% chance of exploitation in the next 30 days, higher than 35.2% of scored vulnerabilities.
Not severe (CVSS 6.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 19 · Related 14Timeline
- 23-12-2016PublishedVulnerability first disclosed.
- 06-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
5 scores · 3 sources · 3 versions- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
EPSS trend
Probability
0.41%
Chance of exploitation in the next 30 days
Percentile
35%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.41% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian2 products
- qemu< 1:2.8+dfsg-1
- debian_linuxEOL8.0
Redhat2 products
- openstack6.0 | 7.0 | 8 | 9 | 10 | 11
- virtualization4.0
Qemu1 product
- qemu≤ 2.7.1 | 2.8.0:rc0 | 2.8.0:rc1 | 2.8.0:rc2
Ubuntu1 product
- qemu< 2.0.0+dfsg-2ubuntu1.33 | < 1:2.5+dfsg-5ubuntu10.11
4 vendors · 6 products
References
11 links
lists.debian.org/debian-lts-announce/2018/09/msg00007.htmlMailing ListX Refsource MLISTThird Party Advisory- www.openwall.com/lists/oss-security/2016/12/09/1Mailing ListX Refsource MLISTPatchThird Party Advisory