Linux Kernel up to 6.12.9/6.13-rc6 sysctl null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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5.5$0-$5k0.00

Summaryinfo

A vulnerability described as critical has been identified in Linux Kernel up to 6.12.9/6.13-rc6. Affected by this vulnerability is an unknown functionality of the component sysctl. Such manipulation leads to null pointer dereference. This vulnerability is documented as CVE-2025-21641. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.12.9/6.13-rc6. Affected by this issue is an unknown code block of the component sysctl. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: mptcp: sysctl: blackhole timeout: avoid using current->nsproxy As mentioned in the previous commit, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'pernet' structure can be obtained from the table->data using container_of().

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2025-21641 since 12/29/2024. There are neither technical details nor an exploit publicly available.

Upgrading to version 6.12.10 or 6.13-rc7 eliminates this vulnerability. Applying the patch 4c74fbdc5ab95b13945be01e6065940b68222db7/92cf7a51bdae24a32c592adcdd59a773ae149289 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-0119). Once again VulDB remains the best source for vulnerability data.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • Dell NetWorker
  • Dell Avamar
  • Dell PowerProtect Data Domain
  • Open Source Linux Kernel

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 6.12.10/6.13-rc7
Patch: 4c74fbdc5ab95b13945be01e6065940b68222db7/92cf7a51bdae24a32c592adcdd59a773ae149289

Timelineinfo

12/29/2024 🔍
01/19/2025 +21 days 🔍
01/19/2025 +0 days 🔍
10/13/2025 +267 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-21641 (🔍)
GCVE (CVE): GCVE-0-2025-21641
GCVE (VulDB): GCVE-100-292556
CERT Bund: WID-SEC-2025-0119 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 01/19/2025 13:16
Updated: 10/13/2025 18:12
Changes: 01/19/2025 13:16 (58), 08/04/2025 03:38 (7), 10/13/2025 18:12 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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