What is CVE-2021-47533?

CVE-2021-47533 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 5.12 onward and patched in 5.15.7 and 5.16. CVE-2021-47533 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47533?

CVE-2021-47533 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-2021-47533?

Yes, CVE-2021-47533 has been patched. Fixed versions include 5.15.7 and 5.16. If you are running Linux kernel 5.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47533 actively exploited?

CVE-2021-47533 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-2021-47533

High

In the Linux kernel, the following vulnerability has been resolved: drm/vc4: kms: Clear the HVS FIFO commit pointer once done Commit 9ec03d7f1ed3 ("drm/vc4: kms: Wait on previous FIFO users before a commit") introduced a wait on the previous commit done on a given HVS FIFO. However, we never cleared that pointer once done. Since drm_crtc_commit_put can free the drm_crtc_commit structure directly if we were the last user, this means that it can lead to a use-after free if we were to duplicate the state, and that stale pointer would even be copied to the new state. Set the pointer to NULL once we're done with the wait so that we don't carry over a pointer to a free'd structure.

Package Linux Kernel

Published 2024-05-24

Last modified 2025-09-18

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-2021-47533 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 5.12 and later are affected. Fixed in 5.15.7, 5.16 and their respective stable series.

Affected from

≥ 5.12

Fixed in

✓ 5.15.7 5.15.x ✓ 5.16

References

2 total

Kernel Git
https://git.kernel.org/stable/c/2931db9a5ed219546cf2ae0546698faf78281b89

Patch
Kernel Git
https://git.kernel.org/stable/c/d134c5ff71c7f2320fc7997f2fbbdedf0c76889a

Patch

Details

CVE ID CVE-2021-47533

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2024-05-24

Modified 2025-09-18

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47533?

CVE-2021-47533 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 5.12 onward and has been patched in 5.15.7 and 5.16. CVE-2021-47533 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47533?

CVE-2021-47533 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-2021-47533?

Yes. CVE-2021-47533 has been patched. Fixed versions include 5.15.7 and 5.16. If you are running Linux kernel 5.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47533 actively exploited?

No. CVE-2021-47533 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.