Is CVE-2021-4206 in the CISA KEV catalog?

No. CVE-2021-4206 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-4206?

CVE-2021-4206 has a CVSS v3 base score of 8.2 (HIGH).

What is the EPSS score for CVE-2021-4206?

CVE-2021-4206 has an EPSS score of 0.83% (53th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-4206?

Upgrade qemu on debian 11 to 1:5.2+dfsg-11+deb11u2 or later. Fixes are available for 25 affected products.

CVE & CISA-KEV Catalog

CVE-2021-4206

HIGH

8.2

CVSS v3

NVD

Description

A flaw was found in the QXL display device emulation in QEMU. An integer overflow in the cursor_alloc() function can lead to the allocation of a small cursor object followed by a subsequent heap-based buffer overflow. This flaw allows a malicious privileged guest user to crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process.

CWE-190Integer Overflow CWE-120Classic Buffer Overflow CWE-131

How to fix

Remediation Available

qemuDebian

Fixed in:1:5.2+dfsg-11+deb11u2CVE-2021-4206

Fixed in:1:7.0+dfsg-1CVE-2021-4206

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-1ubuntu7.40USN-5489-1

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

Fixed in:1:4.2-3ubuntu6.23USN-5489-1

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

Fixed in:1:6.2+dfsg-2ubuntu6.2USN-5489-1

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-1ubuntu7.40USN-5489-1

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

Fixed in:1:4.2-3ubuntu6.23USN-5489-1

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

Fixed in:1:6.2+dfsg-2ubuntu6.2USN-5489-1

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-1ubuntu7.40USN-5489-1

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

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

Fixed in:1:4.2-3ubuntu6.23USN-5489-1

Fixed in:1:6.2+dfsg-2ubuntu6.2USN-5489-1

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-1ubuntu7.40USN-5489-1

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

Fixed in:1:4.2-3ubuntu6.23USN-5489-1

Fixed in:1:6.2+dfsg-2ubuntu6.2USN-5489-1

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-1ubuntu7.40USN-5489-1

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

Fixed in:1:4.2-3ubuntu6.23USN-5489-1

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

Fixed in:1:6.2+dfsg-2ubuntu6.2USN-5489-1

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-1ubuntu7.40USN-5489-1

Fixed in:1:4.2-3ubuntu6.23USN-5489-1

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

Fixed in:1:6.2+dfsg-2ubuntu6.2USN-5489-1

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-1ubuntu7.40USN-5489-1

Fixed in:1:4.2-3ubuntu6.23USN-5489-1

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

Fixed in:1:6.2+dfsg-2ubuntu6.2USN-5489-1

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-1ubuntu7.40USN-5489-1

Fixed in:1:4.2-3ubuntu6.23USN-5489-1

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

Fixed in:1:6.2+dfsg-2ubuntu6.2USN-5489-1

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-1ubuntu7.40USN-5489-1

Fixed in:1:4.2-3ubuntu6.23USN-5489-1

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

Fixed in:1:6.2+dfsg-2ubuntu6.2USN-5489-1

qemu-system-x86-microvmUbuntu

Fixed in:1:4.2-3ubuntu6.23USN-5489-1

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

Fixed in:1:6.2+dfsg-2ubuntu6.2USN-5489-1

qemu-system-x86-xenUbuntu

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

Fixed in:1:4.2-3ubuntu6.23USN-5489-1

Fixed in:1:6.2+dfsg-2ubuntu6.2USN-5489-1

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

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

0.83%probability of exploitation in 30 days

53rdpercentile

Moderate risk: more likely to be exploited than 53% of all known CVEs.

References

Exploit1

starlabs.sg

Third-Party Advisory4

Other references1

security.netapp.com

Embed a live status badge for CVE-2021-4206

Markdown

[![CVE-2021-4206](https://tridentstack.com/cve/badge/CVE-2021-4206.svg)](https://tridentstack.com/cve/CVE-2021-4206)

HTML

<a href="https://tridentstack.com/cve/CVE-2021-4206"><img src="https://tridentstack.com/cve/badge/CVE-2021-4206.svg" alt="CVE-2021-4206"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

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 2025-03-21.