CVE-2021-47323
"Linux watchdog sc520_wdt Use-After-Free"
Description
In the Linux kernel, the following vulnerability has been resolved: watchdog: sc520_wdt: Fix possible use-after-free in wdt_turnoff() 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, 2:40 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
Yes !
Impact Score :
5.9
Exploitability Score :
2.8
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-2021-47323.
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-2021-47323 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47323 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. 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/0015581a79bbf8e521f85dddb7d3e4a66b9f51d4 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/0015581a79bbf8e521f85dddb7d3e4a66b9f51d4 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/2aef07017fae21c3d8acea9656b10e3b9c0f1e04 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/2aef07017fae21c3d8acea9656b10e3b9c0f1e04 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/522e75ed63f67e815d4ec0deace67df22d9ce78e Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/522e75ed63f67e815d4ec0deace67df22d9ce78e Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/7c56c5508dc20a6b133bc669fc34327a6711c24c Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/7c56c5508dc20a6b133bc669fc34327a6711c24c Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/90b7c141132244e8e49a34a4c1e445cce33e07f4 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/90b7c141132244e8e49a34a4c1e445cce33e07f4 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/a173e3b62cf6dd3c4a0a10c8a82eedfcae81a566 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a173e3b62cf6dd3c4a0a10c8a82eedfcae81a566 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/b3c41ea5bc34d8c7b19e230d80e0e555c6f5057d Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/b3c41ea5bc34d8c7b19e230d80e0e555c6f5057d Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/b4565a8a2d6bffb05bfbec11399d261ec16fe373 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/b4565a8a2d6bffb05bfbec11399d261ec16fe373 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/f0feab82f6a0323f54d85e8b512a2be64f83648a Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/f0feab82f6a0323f54d85e8b512a2be64f83648a 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/0015581a79bbf8e521f85dddb7d3e4a66b9f51d4 Added Reference https://git.kernel.org/stable/c/2aef07017fae21c3d8acea9656b10e3b9c0f1e04 Added Reference https://git.kernel.org/stable/c/522e75ed63f67e815d4ec0deace67df22d9ce78e Added Reference https://git.kernel.org/stable/c/7c56c5508dc20a6b133bc669fc34327a6711c24c Added Reference https://git.kernel.org/stable/c/90b7c141132244e8e49a34a4c1e445cce33e07f4 Added Reference https://git.kernel.org/stable/c/a173e3b62cf6dd3c4a0a10c8a82eedfcae81a566 Added Reference https://git.kernel.org/stable/c/b3c41ea5bc34d8c7b19e230d80e0e555c6f5057d Added Reference https://git.kernel.org/stable/c/b4565a8a2d6bffb05bfbec11399d261ec16fe373 Added Reference https://git.kernel.org/stable/c/f0feab82f6a0323f54d85e8b512a2be64f83648a -
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: sc520_wdt: Fix possible use-after-free in wdt_turnoff() 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/0015581a79bbf8e521f85dddb7d3e4a66b9f51d4 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/b4565a8a2d6bffb05bfbec11399d261ec16fe373 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/2aef07017fae21c3d8acea9656b10e3b9c0f1e04 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/522e75ed63f67e815d4ec0deace67df22d9ce78e [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/7c56c5508dc20a6b133bc669fc34327a6711c24c [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/a173e3b62cf6dd3c4a0a10c8a82eedfcae81a566 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/b3c41ea5bc34d8c7b19e230d80e0e555c6f5057d [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/f0feab82f6a0323f54d85e8b512a2be64f83648a [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/90b7c141132244e8e49a34a4c1e445cce33e07f4 [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-2021-47323 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-2021-47323
weaknesses.