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). 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?

No patch is currently available for CVE-2021-47316. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

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

Awaiting data

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

References

The following references provide additional information about CVE-2021-47316 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Cert-Portal
https://cert-portal.siemens.com/productcert/html/ssa-265688.html
Cert-Portal
https://cert-portal.siemens.com/productcert/html/ssa-355557.html
Kernel patch commit
https://git.kernel.org/stable/c/650e6f383a6eb40f7c0a010982a74ab4b6893870
Patch
Kernel patch commit
https://git.kernel.org/stable/c/ab1016d39cc052064e32f25ad18ef8767a0ee3b8
Patch
Kernel patch commit
https://git.kernel.org/stable/c/e79057d15d96ef19de4de6d7e479bae3d58a2a8d
Patch

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 Awaiting data

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) . 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?

No patch is currently available for CVE-2021-47316. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
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.
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. View CWE-476 on MITRE CWE →