What is CVE-2021-47111?

CVE-2021-47111 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, classified as a Use After Free flaw (CWE-416), affecting Linux kernel versions from 5.5 onward and patched in 5.10.43, 5.12.10 and 5.13. CVE-2021-47111 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47111?

CVE-2021-47111 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2021-47111?

Yes, CVE-2021-47111 has been patched. Fixed versions include 5.10.43, 5.12.10 and 5.13. If you are running Linux kernel 5.5 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47111 actively exploited?

CVE-2021-47111 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Use After Free (CWE-416)?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/416.html

CVE-2021-47111

High

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.

Package Linux Kernel

Published 2024-03-15

Last modified 2025-02-27

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Weakness type

CWE-416

CVE-2021-47111 is a Use After Free vulnerability

What is Use After Free?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.5 and later are affected. Fixed in 5.10.43, 5.12.10, 5.13 and their respective stable series.

Affected from

≥ 5.5

Fixed in

✓ 5.10.43 5.10.x ✓ 5.12.10 5.12.x ✓ 5.13

References

3 total

Kernel Git
https://git.kernel.org/stable/c/107866a8eb0b664675a260f1ba0655010fac1e08

Patch
Kernel Git
https://git.kernel.org/stable/c/6b53db8c4c14b4e7256f058d202908b54a7b85b4

Patch
Kernel Git
https://git.kernel.org/stable/c/caec9bcaeb1a5f03f2d406305355c853af10c13e

Patch

Details

CVE ID CVE-2021-47111

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2024-03-15

Modified 2025-02-27

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47111?

CVE-2021-47111 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 5.5 onward and has been patched in 5.10.43, 5.12.10 and 5.13. CVE-2021-47111 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47111?

CVE-2021-47111 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2021-47111?

Yes. CVE-2021-47111 has been patched. Fixed versions include 5.10.43, 5.12.10 and 5.13. If you are running Linux kernel 5.5 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47111 actively exploited?

No. CVE-2021-47111 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.