Is CVE-2021-20203 in the CISA KEV catalog?

No. CVE-2021-20203 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-20203?

CVE-2021-20203 has a CVSS v3 base score of 3.2 (LOW).

What is the EPSS score for CVE-2021-20203?

CVE-2021-20203 has an EPSS score of 0.59% (44th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-20203?

Upgrade qemu on debian 11 to 1:5.2+dfsg-11+deb11u3 or later. Fixes are available for 25 affected products.

CVE & CISA-KEV Catalog

CVE-2021-20203

LOW

3.2

CVSS v3

NVD

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.

CWE-190Integer Overflow

How to fix

Remediation Available

qemuDebian

Fixed in:1:5.2+dfsg-11+deb11u3CVE-2021-20203

Fixed in:1:6.2+dfsg-1CVE-2021-20203

qemuUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1

Fixed in:1:4.2-3ubuntu6.21USN-5307-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

qemu-block-extraUbuntu

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

qemu-commonUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

qemu-guest-agentUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

qemu-keymapsUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

qemu-kvmUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

qemu-systemUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:4.2-3ubuntu6.21USN-5307-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

qemu-system-aarch64Ubuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

qemu-system-armUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1

Fixed in:1:4.2-3ubuntu6.21USN-5307-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

qemu-system-commonUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

qemu-system-dataUbuntu

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

qemu-system-guiUbuntu

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

qemu-system-mipsUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

Fixed in:1:4.2-3ubuntu6.21USN-5307-1

qemu-system-miscUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1

Fixed in:1:4.2-3ubuntu6.21USN-5307-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

qemu-system-ppcUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1

Fixed in:1:4.2-3ubuntu6.21USN-5307-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

qemu-system-s390xUbuntu

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

Fixed in:1:4.2-3ubuntu6.21USN-5307-1

qemu-system-sparcUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

Fixed in:1:4.2-3ubuntu6.21USN-5307-1

qemu-system-x86Ubuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

Fixed in:1:4.2-3ubuntu6.21USN-5307-1

qemu-system-x86-microvmUbuntu

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

Fixed in:1:4.2-3ubuntu6.21USN-5307-1

qemu-system-x86-xenUbuntu

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

Fixed in:1:4.2-3ubuntu6.21USN-5307-1

qemu-userUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

qemu-user-binfmtUbuntu

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

qemu-user-staticUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

qemu-utilsUbuntu

Fixed in:2.0.0+dfsg-2ubuntu1.47+esm6USN-8412-1

Fixed in:1:2.5+dfsg-5ubuntu10.51+esm4USN-8412-1

Fixed in:1:2.11+dfsg-1ubuntu7.42+esm5USN-8412-1

Fixed in:1:4.2-3ubuntu6.30+esm1USN-8412-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredHigh

User InteractionNone

ScopeChanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityLow

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

Exploit Intelligence

0.59%probability of exploitation in 30 days

44thpercentile

Moderate risk: more likely to be exploited than 44% of all known CVEs.

References

Patch2

Third-Party Advisory3

Related Vulnerabilities

Other CWE-190 (Integer Overflow) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2020-16040	Medium	6.5	100%	-	Fix
CVE-2019-11477	High	7.5	99%	-	Fix
CVE-2023-44443	High	7.8	94%	-	Fix
CVE-2014-0569	High	9.3	90%	-	-
CVE-2017-3599	High	7.5	90%	-	Fix
CVE-2023-21716	Critical	9.8	82%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.