CVE & CISA-KEV Catalog

CVE-2020-27821

MEDIUM
6.0
CVSS v3
NVD

Description

A flaw was found in the memory management API of QEMU during the initialization of a memory region cache. This issue could lead to an out-of-bounds write access to the MSI-X table while performing MMIO operations. A guest user may abuse this flaw to crash the QEMU process on the host, resulting in a denial of service. This flaw affects QEMU versions prior to 5.2.0.

How to fix

Remediation Available
qemuDebian
Fixed in:1:5.2+dfsg-3CVE-2020-27821
Fixed in:1:5.2+dfsg-3CVE-2020-27821
Fixed in:1:5.2+dfsg-3CVE-2020-27821
Fixed in:1:5.2+dfsg-3CVE-2020-27821
qemuUbuntu
Fixed in:1:2.5+dfsg-5ubuntu10.49USN-4725-1
Fixed in:1:2.11+dfsg-1ubuntu7.35USN-4725-1
Fixed in:1:4.2-3ubuntu6.12USN-4725-1
qemu-systemUbuntu
Fixed in:1:2.5+dfsg-5ubuntu10.49USN-4725-1
Fixed in:1:2.11+dfsg-1ubuntu7.35USN-4725-1
Fixed in:1:4.2-3ubuntu6.12USN-4725-1
qemu-system-aarch64Ubuntu
Fixed in:1:2.5+dfsg-5ubuntu10.49USN-4725-1
qemu-system-armUbuntu
Fixed in:1:2.5+dfsg-5ubuntu10.49USN-4725-1
Fixed in:1:2.11+dfsg-1ubuntu7.35USN-4725-1
Fixed in:1:4.2-3ubuntu6.12USN-4725-1
qemu-system-mipsUbuntu
Fixed in:1:2.5+dfsg-5ubuntu10.49USN-4725-1
Fixed in:1:2.11+dfsg-1ubuntu7.35USN-4725-1
Fixed in:1:4.2-3ubuntu6.12USN-4725-1
qemu-system-miscUbuntu
Fixed in:1:2.5+dfsg-5ubuntu10.49USN-4725-1
Fixed in:1:2.11+dfsg-1ubuntu7.35USN-4725-1
Fixed in:1:4.2-3ubuntu6.12USN-4725-1
qemu-system-ppcUbuntu
Fixed in:1:2.5+dfsg-5ubuntu10.49USN-4725-1
Fixed in:1:2.11+dfsg-1ubuntu7.35USN-4725-1
Fixed in:1:4.2-3ubuntu6.12USN-4725-1
qemu-system-s390xUbuntu
Fixed in:1:2.5+dfsg-5ubuntu10.49USN-4725-1
Fixed in:1:2.11+dfsg-1ubuntu7.35USN-4725-1
Fixed in:1:4.2-3ubuntu6.12USN-4725-1
qemu-system-sparcUbuntu
Fixed in:1:2.5+dfsg-5ubuntu10.49USN-4725-1
Fixed in:1:2.11+dfsg-1ubuntu7.35USN-4725-1
Fixed in:1:4.2-3ubuntu6.12USN-4725-1
qemu-system-x86Ubuntu
Fixed in:1:2.5+dfsg-5ubuntu10.49USN-4725-1
Fixed in:1:2.11+dfsg-1ubuntu7.35USN-4725-1
Fixed in:1:4.2-3ubuntu6.12USN-4725-1
qemu-system-x86-microvmUbuntu
Fixed in:1:4.2-3ubuntu6.12USN-4725-1
qemu-system-x86-xenUbuntu
Fixed in:1:4.2-3ubuntu6.12USN-4725-1

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
AvailabilityHigh

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

Exploit Intelligence

0.36%probability of exploitation in 30 days
28thpercentile

Low risk: more likely to be exploited than 28% 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
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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.