CVE-2021-20203
published 2021-02-25CVE-2021-20203: 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…
PriorityP410low3.2CVSS 3.1
AVLACLPRHUINSCCNINAL
EPSS
0.59%
44.2th percentile
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.
Affected
19 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | debian_linux | — | — |
| debian | debian_linux | — | — |
| debian | qemu | < qemu 1:6.2+dfsg-1 (bookworm) | qemu 1:6.2+dfsg-1 (bookworm) |
| fedoraproject | fedora | — | — |
| msrc | cbl_mariner_1.0_arm | — | — |
| msrc | cbl_mariner_1.0_x64 | — | — |
| msrc | qemu-img-4.2.0-27.cm1.aarch64.rpm_on_cbl_mariner_1.0_arm | — | — |
| msrc | qemu-img-4.2.0-27.cm1.x86_64.rpm_on_cbl_mariner_1.0_x64 | — | — |
| msrc | qemu-kvm-4.2.0-27.cm1.aarch64.rpm_on_cbl_mariner_1.0_arm | — | — |
| msrc | qemu-kvm-4.2.0-27.cm1.x86_64.rpm_on_cbl_mariner_1.0_x64 | — | — |
| qemu | qemu | <= 5.2.0 | — |
| qemu | qemu | — | — |
| qemu | qemu | >= 0 < 1:5.2+dfsg-11+deb11u3 | 1:5.2+dfsg-11+deb11u3 |
| qemu | qemu | >= 0 < 1:6.2+dfsg-1 | 1:6.2+dfsg-1 |
| qemu | qemu | >= 0 < 1:6.2+dfsg-1 | 1:6.2+dfsg-1 |
| qemu | qemu | >= 0 < 1:6.2+dfsg-1 | 1:6.2+dfsg-1 |
| qemu | qemu | >= 0 < 1:2.11+dfsg-1ubuntu7.39 | 1:2.11+dfsg-1ubuntu7.39 |
| qemu | qemu | >= 0 < 1:4.2-3ubuntu6.21 | 1:4.2-3ubuntu6.21 |
| ubuntu | qemu | — | — |
CVSS provenance
nvdv3.13.2LOWCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:L
nvdv2.02.1LOWAV:L/AC:L/Au:N/C:N/I:N/A:P
osv6.5MEDIUM
vendor_ubuntu6.5MEDIUM
vendor_debian3.2LOW
vendor_msrc3.2LOW
vendor_redhat3.2LOW
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Ubuntu
QEMU regression
vendor_ubuntu·2026-06-28·CVSS 3.8
CVE-2020-11947 [LOW] QEMU regression
Title: QEMU regression
Summary: USN-8412-1 introduced a regression in QEMU
USN-8412-1 fixed vulnerabilities QEMU. On Ubuntu 20.04 LTS, the fix for
CVE-2024-4467 was incomplete and prevented the creation of boot volumes
from qcow2 images. This update fixes the problem.
We apologize for the inconvenience.
Original advisory details:
Felipe Franciosi, Raphael Norwitz, and Peter Turschmid discovered that the
iSCSI block driver in QEMU incorrectly handled certain responses from an
iSCSI server. A remote attacker could possibly use this issue to cause
QEMU to crash, resulting in a denial of service, or possibly execute
arbitrary code. This issue only affected Ubuntu 14.04 LTS. (CVE-2020-1711)
It was discovered that the iSCSI block driver in QEMU incorrectly handled
certain memory operations
Ubuntu
QEMU vulnerabilities
vendor_ubuntu·2026-06-09·CVSS 3.8
CVE-2021-3416 [LOW] QEMU vulnerabilities
Title: QEMU vulnerabilities
Summary: Several security issues were fixed in QEMU.
Felipe Franciosi, Raphael Norwitz, and Peter Turschmid discovered that the
iSCSI block driver in QEMU incorrectly handled certain responses from an
iSCSI server. A remote attacker could possibly use this issue to cause QEMU
to crash, resulting in a denial of service, or possibly execute arbitrary
code. This issue only affected Ubuntu 14.04 LTS. (CVE-2020-1711)
It was discovered that the iSCSI block driver in QEMU incorrectly handled
certain memory operations, leading to a heap-based buffer over-read. An
attacker could possibly use this issue to expose sensitive information from
the host. This issue only affected Ubuntu 14.04 LTS. (CVE-2020-11947)
Ziming Zhang discovered that the SM501 display driver in QEM
Ubuntu
QEMU vulnerabilities
vendor_ubuntu·2022-02-28·CVSS 6.5
CVE-2021-3544 [MEDIUM] QEMU vulnerabilities
Title: QEMU vulnerabilities
Summary: Several security issues were fixed in QEMU.
Gaoning Pan discovered that QEMU incorrectly handled the floppy disk
emulator. An attacker inside the guest could use this issue to cause QEMU
to crash, resulting in a denial of service. (CVE-2021-20196)
Gaoning Pan discovered that the QEMU vmxnet3 NIC emulator incorrectly
handled certain values. An attacker inside the guest could use this issue
to cause QEMU to crash, resulting in a denial of service. (CVE-2021-20203)
It was discovered that the QEMU vhost-user GPU device contained several
security issues. An attacker inside the guest could use these issues to
cause QEMU to crash, resulting in a denial of service, leak sensitive
information, or possibly execute arbitrary code. This issue only affected
Ubun
Microsoft
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
vendor_msrc·2021-02-09·CVSS 3.2
CVE-2021-20203 [LOW] CWE-190 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
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.
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025.
Red Hat
qemu: Failed malloc in vmxnet3_activate_device() in hw/net/vmxnet3.c
vendor_redhat·2021-01-30·CVSS 3.2
CVE-2021-20203 [LOW] CWE-190 qemu: Failed malloc in vmxnet3_activate_device() in hw/net/vmxnet3.c
qemu: Failed malloc in vmxnet3_activate_device() in hw/net/vmxnet3.c
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.
An integer overflow flaw was found in the vmxnet3 NIC emulator of QEMU. This issue occurs when a guest supplies invalid values for the rx/tx queue size or other NIC parameters. This flaw allows a privileged guest user to crash the QEMU process on the host, resulting in a denial of service.
Statement: This issue does not affect the versions of the qemu-kvm package as shipped with Red Hat Enterprise Linux 5, 6, 7 and
Debian
CVE-2021-20203: qemu - An integer overflow issue was found in the vmxnet3 NIC emulator of the QEMU for ...
vendor_debian·2021·CVSS 3.2
CVE-2021-20203 [LOW] CVE-2021-20203: qemu - An integer overflow issue was found in the vmxnet3 NIC emulator of the QEMU for ...
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.
Scope: local
bookworm: resolved (fixed in 1:6.2+dfsg-1)
bullseye: resolved (fixed in 1:5.2+dfsg-11+deb11u3)
forky: resolved (fixed in 1:6.2+dfsg-1)
sid: resolved (fixed in 1:6.2+dfsg-1)
trixie: resolved (fixed in 1:6.2+dfsg-1)
GHSA
GHSA-8gqc-j7wm-6g58: An integer overflow issue was found in the vmxnet3 NIC emulator of the QEMU for versions up to v5
ghsa_unreviewed·2022-05-24
CVE-2021-20203 [LOW] CWE-190 GHSA-8gqc-j7wm-6g58: An integer overflow issue was found in the vmxnet3 NIC emulator of the QEMU for versions up to v5
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.
OSV
qemu vulnerabilities
osv·2022-02-28·CVSS 6.5
CVE-2021-20196 [MEDIUM] qemu vulnerabilities
qemu vulnerabilities
Gaoning Pan discovered that QEMU incorrectly handled the floppy disk
emulator. An attacker inside the guest could use this issue to cause QEMU
to crash, resulting in a denial of service. (CVE-2021-20196)
Gaoning Pan discovered that the QEMU vmxnet3 NIC emulator incorrectly
handled certain values. An attacker inside the guest could use this issue
to cause QEMU to crash, resulting in a denial of service. (CVE-2021-20203)
It was discovered that the QEMU vhost-user GPU device contained several
security issues. An attacker inside the guest could use these issues to
cause QEMU to crash, resulting in a denial of service, leak sensitive
information, or possibly execute arbitrary code. This issue only affected
Ubuntu 21.10. (CVE-2021-3544, CVE-2021-3545, CVE-2021-3546)
It w
OSV
CVE-2021-20203: An integer overflow issue was found in the vmxnet3 NIC emulator of the QEMU for versions up to v5
osv·2021-02-25·CVSS 3.2
CVE-2021-20203 [LOW] CVE-2021-20203: An integer overflow issue was found in the vmxnet3 NIC emulator of the QEMU for versions up to v5
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.
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
https://bugs.launchpad.net/qemu/+bug/1913873https://bugzilla.redhat.com/show_bug.cgi?id=1922441https://lists.debian.org/debian-lts-announce/2021/04/msg00009.htmlhttps://lists.debian.org/debian-lts-announce/2022/09/msg00008.htmlhttps://security.gentoo.org/glsa/202208-27https://bugs.launchpad.net/qemu/+bug/1913873https://bugzilla.redhat.com/show_bug.cgi?id=1922441https://lists.debian.org/debian-lts-announce/2021/04/msg00009.htmlhttps://lists.debian.org/debian-lts-announce/2022/09/msg00008.htmlhttps://security.gentoo.org/glsa/202208-27
2021-02-25
Published