CVE & CISA-KEV Catalog

CVE-2021-47111

HIGH
7.8
CVSS v3
NVD

Description

In the Linux kernel, the following vulnerability has been resolved: xen-netback: take a reference to the RX task thread Do this in order to prevent the task from being freed if the thread returns (which can be triggered by the frontend) before the call to kthread_stop done as part of the backend tear down. Not taking the reference will lead to a use-after-free in that scenario. Such reference was taken before but dropped as part of the rework done in 2ac061ce97f4. Reintroduce the reference taking and add a comment this time explaining why it's needed. This is XSA-374 / CVE-2021-28691.

How to fix

Remediation Available
linuxDebian
Fixed in:5.10.46-1CVE-2021-47111
Fixed in:5.10.46-1CVE-2021-47111
Fixed in:5.10.46-1CVE-2021-47111
Fixed in:5.10.46-1CVE-2021-47111

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

0.24%probability of exploitation in 30 days
14thpercentile

Low risk: more likely to be exploited than 14% 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
Embed a live status badge for CVE-2021-47111
CVE-2021-47111 severity badge

Markdown

[![CVE-2021-47111](https://tridentstack.com/cve/badge/CVE-2021-47111.svg)](https://tridentstack.com/cve/CVE-2021-47111)

HTML

<a href="https://tridentstack.com/cve/CVE-2021-47111"><img src="https://tridentstack.com/cve/badge/CVE-2021-47111.svg" alt="CVE-2021-47111"></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 2025-02-27.