CVE & CISA-KEV Catalog

CVE-2021-3638

MEDIUM
6.5
CVSS v3
NVD

Description

An out-of-bounds memory access flaw was found in the ATI VGA device emulation of QEMU. This flaw occurs in the ati_2d_blt() routine while handling MMIO write operations when the guest provides invalid values for the destination display parameters. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service.

How to fix

Remediation Available
qemuDebian
Fixed in:1:5.2+dfsg-11+deb11u1CVE-2021-3638
Fixed in:1:6.1+dfsg-6CVE-2021-3638
Fixed in:1:6.1+dfsg-6CVE-2021-3638
Fixed in:1:6.1+dfsg-6CVE-2021-3638
qemuUbuntu
Fixed in:1:4.2-3ubuntu6.28USN-6567-1
Fixed in:1:6.2+dfsg-2ubuntu6.16USN-6567-1
Fixed in:1:7.2+dfsg-5ubuntu2.4USN-6567-1
Fixed in:1:8.0.4+dfsg-1ubuntu3.23.10.2USN-6567-1
qemu-systemUbuntu
Fixed in:1:4.2-3ubuntu6.28USN-6567-1
Fixed in:1:7.2+dfsg-5ubuntu2.4USN-6567-1
Fixed in:1:8.0.4+dfsg-1ubuntu3.23.10.2USN-6567-1
qemu-system-armUbuntu
Fixed in:1:4.2-3ubuntu6.28USN-6567-1
Fixed in:1:6.2+dfsg-2ubuntu6.16USN-6567-1
Fixed in:1:7.2+dfsg-5ubuntu2.4USN-6567-1
Fixed in:1:8.0.4+dfsg-1ubuntu3.23.10.2USN-6567-1
qemu-system-mipsUbuntu
Fixed in:1:4.2-3ubuntu6.28USN-6567-1
Fixed in:1:6.2+dfsg-2ubuntu6.16USN-6567-1
Fixed in:1:7.2+dfsg-5ubuntu2.4USN-6567-1
Fixed in:1:8.0.4+dfsg-1ubuntu3.23.10.2USN-6567-1
qemu-system-miscUbuntu
Fixed in:1:4.2-3ubuntu6.28USN-6567-1
Fixed in:1:6.2+dfsg-2ubuntu6.16USN-6567-1
Fixed in:1:7.2+dfsg-5ubuntu2.4USN-6567-1
Fixed in:1:8.0.4+dfsg-1ubuntu3.23.10.2USN-6567-1
qemu-system-ppcUbuntu
Fixed in:1:4.2-3ubuntu6.28USN-6567-1
Fixed in:1:6.2+dfsg-2ubuntu6.16USN-6567-1
Fixed in:1:7.2+dfsg-5ubuntu2.4USN-6567-1
Fixed in:1:8.0.4+dfsg-1ubuntu3.23.10.2USN-6567-1
qemu-system-s390xUbuntu
Fixed in:1:4.2-3ubuntu6.28USN-6567-1
Fixed in:1:6.2+dfsg-2ubuntu6.16USN-6567-1
Fixed in:1:7.2+dfsg-5ubuntu2.4USN-6567-1
Fixed in:1:8.0.4+dfsg-1ubuntu3.23.10.2USN-6567-1
qemu-system-sparcUbuntu
Fixed in:1:4.2-3ubuntu6.28USN-6567-1
Fixed in:1:6.2+dfsg-2ubuntu6.16USN-6567-1
Fixed in:1:7.2+dfsg-5ubuntu2.4USN-6567-1
Fixed in:1:8.0.4+dfsg-1ubuntu3.23.10.2USN-6567-1
qemu-system-x86Ubuntu
Fixed in:1:4.2-3ubuntu6.28USN-6567-1
Fixed in:1:6.2+dfsg-2ubuntu6.16USN-6567-1
Fixed in:1:7.2+dfsg-5ubuntu2.4USN-6567-1
Fixed in:1:8.0.4+dfsg-1ubuntu3.23.10.2USN-6567-1
qemu-system-x86-microvmUbuntu
Fixed in:1:4.2-3ubuntu6.28USN-6567-1
Fixed in:1:6.2+dfsg-2ubuntu6.16USN-6567-1
qemu-system-x86-xenUbuntu
Fixed in:1:4.2-3ubuntu6.28USN-6567-1
Fixed in:1:6.2+dfsg-2ubuntu6.16USN-6567-1
Fixed in:1:7.2+dfsg-5ubuntu2.4USN-6567-1
Fixed in:1:8.0.4+dfsg-1ubuntu3.23.10.2USN-6567-1
qemu-system-xenUbuntu
Fixed in:1:7.2+dfsg-5ubuntu2.4USN-6567-1
Fixed in:1:8.0.4+dfsg-1ubuntu3.23.10.2USN-6567-1

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 RequiredLow
User InteractionNone
ScopeChanged

Impact

ConfidentialityNone
IntegrityNone
AvailabilityHigh

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

Exploit Intelligence

0.43%probability of exploitation in 30 days
35thpercentile

Low risk: more likely to be exploited than 35% of all known CVEs.

References

Related Vulnerabilities

Other CWE-787 (Out-of-bounds Write) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2025-22457Critical9.0100%KEV + RansomFix
CVE-2025-0282Critical9.0100%KEV + Ransom-
CVE-2015-3113Critical9.8100%KEVFix
CVE-2021-20038Critical9.8100%KEV + Ransom-
CVE-2023-4863High8.8100%KEVFix
CVE-2020-16040Medium6.5100%-Fix
Embed a live status badge for CVE-2021-3638
CVE-2021-3638 severity badge

Markdown

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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.