What is CVE-2021-47356?

CVE-2021-47356 is a High severity Linux kernel vulnerability with a CVSS score of 7.7 out of 10, classified as a Use After Free flaw (CWE-416). CVE-2021-47356 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47356?

CVE-2021-47356 has a CVSS score of 7.7 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

Is there a patch available for CVE-2021-47356?

No patch is currently available for CVE-2021-47356. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2021-47356 actively exploited?

CVE-2021-47356 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-2021-47356

High

In the Linux kernel, the following vulnerability has been resolved: mISDN: fix possible use-after-free in HFC_cleanup() This module's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself.

Package Linux Kernel

Published 2024-05-21

Last modified 2025-04-02

CVSS version 3.1

Patch available

Awaiting data

CVSS 3.1 score

7.7

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

High

Availability

High

Vector string

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

Weakness type

CWE-416

CVE-2021-47356 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

References

The following references provide additional information about CVE-2021-47356 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/009fc857c5f6fda81f2f7dd851b2d54193a8e733
Patch
Kernel patch commit
https://git.kernel.org/stable/c/3ecd228c636ee17c14662729737fa07242a93cb0
Patch
Kernel patch commit
https://git.kernel.org/stable/c/49331c07ef0f8fdfa42b30ba6a83a657b29d7fbe
Patch

9 patch commits total View all on NVD

Details

CVE ID CVE-2021-47356

Severity High

CVSS score 7.7 / 10

CVSS version 3.1

Published 2024-05-21

Modified 2025-04-02

KEV No

Patch Awaiting data

Package linux

Frequently asked questions

What is CVE-2021-47356?

CVE-2021-47356 is a High severity Linux kernel vulnerability with a CVSS score of 7.7 out of 10 , classified as an Use After Free flaw (CWE-416) . CVE-2021-47356 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47356?

CVE-2021-47356 has a CVSS score of 7.7 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.
Is there a patch available for CVE-2021-47356?

No patch is currently available for CVE-2021-47356. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2021-47356 actively exploited?

No — CVE-2021-47356 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (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. View CWE-416 on MITRE CWE →