7.5
HIGH
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 :

July 3, 2024, 1:37 a.m.

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Remotely Exploitable :

Yes !

Impact Score :

5.9

Exploitability Score :

1.6
Affected Products

The following products are affected by CVE-2021-47259 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel

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.

  • 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]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
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.

CVSS31 - Vulnerability Scoring System
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