CVE & CISA-KEV Catalog

CVE-2021-3748

HIGH
7.5
CVSS v3
NVD

Description

A use-after-free vulnerability was found in the virtio-net device of QEMU. It could occur when the descriptor's address belongs to the non direct access region, due to num_buffers being set after the virtqueue elem has been unmapped. A malicious guest could use this flaw to crash QEMU, resulting in a denial of service condition, or potentially execute code on the host with the privileges of the QEMU process.

How to fix

Remediation Available
qemuDebian
Fixed in:1:5.2+dfsg-11+deb11u1CVE-2021-3748
Fixed in:1:6.1+dfsg-6CVE-2021-3748
Fixed in:1:6.1+dfsg-6CVE-2021-3748
Fixed in:1:6.1+dfsg-6CVE-2021-3748
qemuUbuntu
Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1
Fixed in:1:4.2-3ubuntu6.21USN-5307-1
qemu-systemUbuntu
Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1
Fixed in:1:4.2-3ubuntu6.21USN-5307-1
qemu-system-armUbuntu
Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1
Fixed in:1:4.2-3ubuntu6.21USN-5307-1
qemu-system-mipsUbuntu
Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1
Fixed in:1:4.2-3ubuntu6.21USN-5307-1
qemu-system-miscUbuntu
Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1
Fixed in:1:4.2-3ubuntu6.21USN-5307-1
qemu-system-ppcUbuntu
Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1
Fixed in:1:4.2-3ubuntu6.21USN-5307-1
qemu-system-s390xUbuntu
Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1
Fixed in:1:4.2-3ubuntu6.21USN-5307-1
qemu-system-sparcUbuntu
Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1
Fixed in:1:4.2-3ubuntu6.21USN-5307-1
qemu-system-x86Ubuntu
Fixed in:1:2.11+dfsg-1ubuntu7.39USN-5307-1
Fixed in:1:4.2-3ubuntu6.21USN-5307-1
qemu-system-x86-microvmUbuntu
Fixed in:1:4.2-3ubuntu6.21USN-5307-1
qemu-system-x86-xenUbuntu
Fixed in:1:4.2-3ubuntu6.21USN-5307-1

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 ComplexityHigh
Privileges RequiredHigh
User InteractionNone
ScopeChanged

Impact

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

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

Exploit Intelligence

0.52%probability of exploitation in 30 days
40thpercentile

Moderate risk: more likely to be exploited than 40% of all known CVEs.

References

Related Vulnerabilities

Other CWE-416 (Use After Free) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2019-0708Critical9.8100%KEV + Ransom-
CVE-2021-31166Critical9.8100%KEVFix
CVE-2015-5119Critical9.899%KEV-
CVE-2010-3962High8.197%KEV-
CVE-2015-0313Critical9.896%KEVFix
CVE-2017-9798High7.595%-Fix
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CVE-2021-3748 severity badge

Markdown

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HTML

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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.