Low severity · published Feb 25, 2021
CVE-2021-20203
An integer overflow issue was found in the vmxnet3 NIC emulator of the QEMU for versions up to v5.2.0
3.2
CVSS
0.6%
EPSS
No
On KEV
Description
An integer overflow issue was found in the vmxnet3 NIC emulator of the QEMU for versions up to v5.2.0. It may occur if a guest was to supply invalid values for rx/tx queue size or other NIC parameters. A privileged guest user may use this flaw to crash the QEMU process on the host resulting in DoS scenario.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:L
Attack vector
Local
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 48% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DL
Debian Linux · Debian
9.0; 10.0 · source: NVD
FE
Fedora · Fedoraproject
33 · source: NVD
QE
Qemu · Qemu
through 5.2.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-20203
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-20203
Exploit
https://bugs.launchpad.net/qemu/+bug/1913873
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=1922441
Mailing List
https://lists.debian.org/debian-lts-announce/2021/04/msg00009.html
Mailing List
https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html
Third Party Advisory
https://security.gentoo.org/glsa/202208-27
More from Debian Linux
10.0
CVE-2025-32433
Erlang/OTP SSH Vulnerable to Pre-Authentication RCE
10.0
CVE-2025-24201
Apple Multiple Products WebKit Out-of-Bounds Write Vulnerability
10.0
CVE-2021-44228
Apache Log4j2 JNDI features do not protect against attacker controlled LDAP and other JNDI related endpoints
10.0
CVE-2015-3306
ProFTPD Improper Access Control Vulnerability
9.8
CVE-2026-111497
Out-of-Bounds Write in Google Brotli Decoder