What is CVE-2021-47316?

CVE-2021-47316 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, classified as a NULL Pointer Dereference flaw (CWE-476), affecting Linux kernel versions from 5.13 onward and patched in 5.13.4 and 5.14. CVE-2021-47316 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47316?

CVE-2021-47316 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2021-47316?

Yes, CVE-2021-47316 has been patched. Fixed versions include 5.13.4 and 5.14. If you are running Linux kernel 5.13 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47316 actively exploited?

CVE-2021-47316 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is NULL Pointer Dereference (CWE-476)?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/476.html

CVE-2021-47316

Medium

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix NULL dereference in nfs3svc_encode_getaclres In error cases the dentry may be NULL. Before 20798dfe249a, the encoder also checked dentry and d_really_is_positive(dentry), but that looks like overkill to me--zero status should be enough to guarantee a positive dentry. This isn't the first time we've seen an error-case NULL dereference hidden in the initialization of a local variable in an xdr encoder. But I went back through the other recent rewrites and didn't spot any similar bugs.

Package Linux Kernel

Published 2024-05-21

Last modified 2026-05-12

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Weakness type

CWE-476

CVE-2021-47316 is a NULL Pointer Dereference vulnerability

What is NULL Pointer Dereference?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.13 and later are affected. Fixed in 5.13.4, 5.14 and their respective stable series.

Affected from

≥ 5.13

Fixed in

✓ 5.13.4 5.13.x ✓ 5.14

References

5 total

Kernel Git
https://git.kernel.org/stable/c/650e6f383a6eb40f7c0a010982a74ab4b6893870

Patch
Kernel Git
https://git.kernel.org/stable/c/ab1016d39cc052064e32f25ad18ef8767a0ee3b8

Patch
Kernel Git
https://git.kernel.org/stable/c/e79057d15d96ef19de4de6d7e479bae3d58a2a8d

Patch
Cert-Portal
https://cert-portal.siemens.com/productcert/html/ssa-265688.html
Cert-Portal
https://cert-portal.siemens.com/productcert/html/ssa-355557.html

Details

CVE ID CVE-2021-47316

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-05-21

Modified 2026-05-12

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47316?

CVE-2021-47316 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 5.13 onward and has been patched in 5.13.4 and 5.14. CVE-2021-47316 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47316?

CVE-2021-47316 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2021-47316?

Yes. CVE-2021-47316 has been patched. Fixed versions include 5.13.4 and 5.14. If you are running Linux kernel 5.13 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47316 actively exploited?

No. CVE-2021-47316 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.