CVE-2021-47324
watchdog: Fix possible use-after-free in wdt_startup()
Description
In the Linux kernel, the following vulnerability has been resolved: watchdog: Fix possible use-after-free in wdt_startup() This module's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself.
INFO
Published Date :
May 21, 2024, 3:15 p.m.
Last Modified :
April 2, 2025, 2:39 p.m.
Remotely Exploit :
Yes !
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update the Linux kernel to a patched version.
- Reboot the system to apply the kernel update.
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-2021-47324.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47324 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-2021-47324
weaknesses.
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-2021-47324 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47324 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.
-
Initial Analysis by [email protected]
Apr. 02, 2025
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.5 up to (excluding) 5.10.52 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.12.19 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.13 up to (excluding) 5.13.4 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.5 up to (excluding) 4.9.276 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.10 up to (excluding) 4.14.240 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.15 up to (excluding) 4.19.198 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions up to (excluding) 4.4.276 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.20 up to (excluding) 5.4.134 Added Reference Type CVE: https://git.kernel.org/stable/c/0ac50a76cf3cd63db000648b3b19f3f98b8aaa76 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/0ac50a76cf3cd63db000648b3b19f3f98b8aaa76 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/146cc288fb80c662c9c35e7bc58325d1ac0a7875 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/146cc288fb80c662c9c35e7bc58325d1ac0a7875 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/63a3dc24bd053792f84cb4eef0168b1266202a02 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/63a3dc24bd053792f84cb4eef0168b1266202a02 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/862f2b5a7c38762ac9e369daefbf361a91aca685 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/862f2b5a7c38762ac9e369daefbf361a91aca685 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/8adbbe6c86bb13e14f8a19e036ae5f4f5661fd90 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/8adbbe6c86bb13e14f8a19e036ae5f4f5661fd90 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/a397cb4576fc2fc802562418b3a50b8f67d60d31 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a397cb4576fc2fc802562418b3a50b8f67d60d31 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/b4ebf4a4692e84163a69444c70ad515de06e2259 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/b4ebf4a4692e84163a69444c70ad515de06e2259 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/c08a6b31e4917034f0ed0cb457c3bb209576f542 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/c08a6b31e4917034f0ed0cb457c3bb209576f542 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/dc9403097be52d57a5c9c35efa9be79d166a78af Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/dc9403097be52d57a5c9c35efa9be79d166a78af 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/0ac50a76cf3cd63db000648b3b19f3f98b8aaa76 Added Reference https://git.kernel.org/stable/c/146cc288fb80c662c9c35e7bc58325d1ac0a7875 Added Reference https://git.kernel.org/stable/c/63a3dc24bd053792f84cb4eef0168b1266202a02 Added Reference https://git.kernel.org/stable/c/862f2b5a7c38762ac9e369daefbf361a91aca685 Added Reference https://git.kernel.org/stable/c/8adbbe6c86bb13e14f8a19e036ae5f4f5661fd90 Added Reference https://git.kernel.org/stable/c/a397cb4576fc2fc802562418b3a50b8f67d60d31 Added Reference https://git.kernel.org/stable/c/b4ebf4a4692e84163a69444c70ad515de06e2259 Added Reference https://git.kernel.org/stable/c/c08a6b31e4917034f0ed0cb457c3bb209576f542 Added Reference https://git.kernel.org/stable/c/dc9403097be52d57a5c9c35efa9be79d166a78af -
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:L/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: watchdog: Fix possible use-after-free in wdt_startup() This module's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself. Added Reference kernel.org https://git.kernel.org/stable/c/63a3dc24bd053792f84cb4eef0168b1266202a02 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/862f2b5a7c38762ac9e369daefbf361a91aca685 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/0ac50a76cf3cd63db000648b3b19f3f98b8aaa76 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/dc9403097be52d57a5c9c35efa9be79d166a78af [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/146cc288fb80c662c9c35e7bc58325d1ac0a7875 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/a397cb4576fc2fc802562418b3a50b8f67d60d31 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/b4ebf4a4692e84163a69444c70ad515de06e2259 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/8adbbe6c86bb13e14f8a19e036ae5f4f5661fd90 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/c08a6b31e4917034f0ed0cb457c3bb209576f542 [No types assigned]