What is CVE-2021-47259?

CVE-2021-47259 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10, classified as a Use After Free flaw (CWE-416). CVE-2021-47259 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47259?

CVE-2021-47259 has a CVSS score of 7.5 out of 10, rated High severity. The vector string is CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2021-47259?

No patch is currently available for CVE-2021-47259. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2021-47259 actively exploited?

CVE-2021-47259 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-2021-47259

High

In the Linux kernel, the following vulnerability has been resolved: NFS: Fix use-after-free in nfs4_init_client() KASAN reports a use-after-free when attempting to mount two different exports through two different NICs that belong to the same server. Olga was able to hit this with kernels starting somewhere between 5.7 and 5.10, but I traced the patch that introduced the clear_bit() call to 4.13. So something must have changed in the refcounting of the clp pointer to make this call to nfs_put_client() the very last one.

Package Linux Kernel

Published 2024-05-21

Last modified 2025-04-04

CVSS version 3.1

Patch available

Awaiting data

CVSS 3.1 score

7.5

out of 10

High

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Weakness type

CWE-416

CVE-2021-47259 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-2021-47259 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/3e3c7ebbfac152d08be75c92802a64a1f6471a15
Patch
Kernel patch commit
https://git.kernel.org/stable/c/42c10b0db064e45f5c5ae7019bbf2168ffab766c
Patch
Kernel patch commit
https://git.kernel.org/stable/c/476bdb04c501fc64bf3b8464ffddefc8dbe01577
Patch

6 patch commits total View all on NVD

Details

CVE ID CVE-2021-47259

Severity High

CVSS score 7.5 / 10

CVSS version 3.1

Published 2024-05-21

Modified 2025-04-04

KEV No

Patch Awaiting data

Package linux

Frequently asked questions

What is CVE-2021-47259?

CVE-2021-47259 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10 , classified as an Use After Free flaw (CWE-416) . CVE-2021-47259 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47259?

CVE-2021-47259 has a CVSS score of 7.5 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2021-47259?

No patch is currently available for CVE-2021-47259. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2021-47259 actively exploited?

No — CVE-2021-47259 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 →