CVE & CISA-KEV Catalog

CVE-2021-28691

HIGH
7.8
CVSS v3
NVD

Description

Guest triggered use-after-free in Linux xen-netback A malicious or buggy network PV frontend can force Linux netback to disable the interface and terminate the receive kernel thread associated with queue 0 in response to the frontend sending a malformed packet. Such kernel thread termination will lead to a use-after-free in Linux netback when the backend is destroyed, as the kernel thread associated with queue 0 will have already exited and thus the call to kthread_stop will be performed against a stale pointer.

CWE-416Use After Free

How to fix

Remediation Available
linuxDebian
Fixed in:5.10.46-1CVE-2021-28691
Fixed in:5.10.46-1CVE-2021-28691
Fixed in:5.10.46-1CVE-2021-28691
Fixed in:5.10.46-1CVE-2021-28691
linux-aws-5.8Ubuntu
Fixed in:5.8.0-1042.44~20.04.1USN-5050-1
linux-azure-5.8Ubuntu
Fixed in:5.8.0-1040.43~20.04.1USN-5050-1
linux-gcp-5.8Ubuntu
Fixed in:5.8.0-1039.41USN-5050-1
linux-hwe-5.11Ubuntu
Fixed in:5.11.0-27.29~20.04.1USN-5046-1
linux-image-5.10.0-1038-oemUbuntu
Fixed in:5.10.0-1038.40USN-5015-1
linux-image-5.11.0-27-genericUbuntu
Fixed in:5.11.0-27.29~20.04.1USN-5046-1
linux-image-5.11.0-27-generic-64kUbuntu
Fixed in:5.11.0-27.29~20.04.1USN-5046-1
linux-image-5.11.0-27-generic-lpaeUbuntu
Fixed in:5.11.0-27.29~20.04.1USN-5046-1
linux-image-5.11.0-27-lowlatencyUbuntu
Fixed in:5.11.0-27.29~20.04.1USN-5046-1
linux-image-5.8.0-1038-oracleUbuntu
Fixed in:5.8.0-1038.39~20.04.1USN-5050-1
linux-image-5.8.0-1039-gcpUbuntu
Fixed in:5.8.0-1039.41USN-5050-1
linux-image-5.8.0-1040-azureUbuntu
Fixed in:5.8.0-1040.43~20.04.1USN-5050-1
linux-image-5.8.0-1042-awsUbuntu
Fixed in:5.8.0-1042.44~20.04.1USN-5050-1
linux-image-awsUbuntu
Fixed in:5.8.0.1042.44~20.04.14USN-5050-1
linux-image-azureUbuntu
Fixed in:5.8.0.1040.43~20.04.12USN-5050-1
linux-image-gcpUbuntu
Fixed in:5.8.0.1039.14USN-5050-1
linux-image-generic-64k-hwe-20.04Ubuntu
Fixed in:5.11.0.27.29~20.04.11USN-5046-1
linux-image-generic-hwe-20.04Ubuntu
Fixed in:5.11.0.27.29~20.04.11USN-5046-1
linux-image-generic-lpae-hwe-20.04Ubuntu
Fixed in:5.11.0.27.29~20.04.11USN-5046-1
linux-image-lowlatency-hwe-20.04Ubuntu
Fixed in:5.11.0.27.29~20.04.11USN-5046-1
linux-image-oem-20.04Ubuntu
Fixed in:5.10.0.1038.40USN-5015-1
linux-image-oem-20.04bUbuntu
Fixed in:5.10.0.1038.40USN-5015-1
linux-image-oracleUbuntu
Fixed in:5.8.0.1038.39~20.04.14USN-5050-1
linux-image-virtual-hwe-20.04Ubuntu
Fixed in:5.11.0.27.29~20.04.11USN-5046-1
linux-oem-5.10Ubuntu
Fixed in:5.10.0-1038.40USN-5015-1
linux-oracle-5.8Ubuntu
Fixed in:5.8.0-1038.39~20.04.1USN-5050-1

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
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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-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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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.