CVE-2021-47259
Linux Kernel NFS Use-After-Free Vulnerability
Description
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.
INFO
Published Date :
May 21, 2024, 3:15 p.m.
Last Modified :
April 4, 2025, 2:30 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
Yes !
Impact Score :
5.9
Exploitability Score :
1.6
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-47259.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-47259 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47259 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Apr. 04, 2025
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.13:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.12.11 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.13 up to (excluding) 4.14.237 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.15 up to (excluding) 4.19.195 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.20 up to (excluding) 5.4.126 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.5 up to (excluding) 5.10.44 Added Reference Type CVE: https://git.kernel.org/stable/c/3e3c7ebbfac152d08be75c92802a64a1f6471a15 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/3e3c7ebbfac152d08be75c92802a64a1f6471a15 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/42c10b0db064e45f5c5ae7019bbf2168ffab766c Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/42c10b0db064e45f5c5ae7019bbf2168ffab766c Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/476bdb04c501fc64bf3b8464ffddefc8dbe01577 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/476bdb04c501fc64bf3b8464ffddefc8dbe01577 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/72651c6579a25317a90536181d311c663d0329ab Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/72651c6579a25317a90536181d311c663d0329ab Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/c3b6cf64dfe4ef96e7341508d50d6998da7062c7 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/c3b6cf64dfe4ef96e7341508d50d6998da7062c7 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/c7eab9e2d7b4e983ce280276fb920af649955897 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/c7eab9e2d7b4e983ce280276fb920af649955897 Types: Patch -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/3e3c7ebbfac152d08be75c92802a64a1f6471a15 Added Reference https://git.kernel.org/stable/c/42c10b0db064e45f5c5ae7019bbf2168ffab766c Added Reference https://git.kernel.org/stable/c/476bdb04c501fc64bf3b8464ffddefc8dbe01577 Added Reference https://git.kernel.org/stable/c/72651c6579a25317a90536181d311c663d0329ab Added Reference https://git.kernel.org/stable/c/c3b6cf64dfe4ef96e7341508d50d6998da7062c7 Added Reference https://git.kernel.org/stable/c/c7eab9e2d7b4e983ce280276fb920af649955897 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 03, 2024
Action Type Old Value New Value Added CWE CISA-ADP CWE-416 Added CVSS V3.1 CISA-ADP AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 21, 2024
Action Type Old Value New Value Added Description 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. Added Reference kernel.org https://git.kernel.org/stable/c/c7eab9e2d7b4e983ce280276fb920af649955897 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/42c10b0db064e45f5c5ae7019bbf2168ffab766c [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/3e3c7ebbfac152d08be75c92802a64a1f6471a15 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/c3b6cf64dfe4ef96e7341508d50d6998da7062c7 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/72651c6579a25317a90536181d311c663d0329ab [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/476bdb04c501fc64bf3b8464ffddefc8dbe01577 [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47259 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-47259
weaknesses.