VDB-334639 · CVE-2025-40279 · EUVD-2025-201576

Linux Kernel up to 5.15.196/6.1.158/6.6.116/6.12.58/6.17.8 Netlink Message tcf_connmark_dump opt uninitialized pointer

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3.4	$0-$5k	0.00

Summaryinfo

A vulnerability marked as critical has been reported in Linux Kernel up to 5.15.196/6.1.158/6.6.116/6.12.58/6.17.8. This affects the function tcf_connmark_dump of the component Netlink Message Handler. This manipulation of the argument opt causes uninitialized pointer. The identification of this vulnerability is CVE-2025-40279. There is no exploit available. It is suggested to upgrade the affected component. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Detailsinfo

A vulnerability classified as problematic was found in Linux Kernel up to 5.15.196/6.1.158/6.6.116/6.12.58/6.17.8. Affected by this vulnerability is the function tcf_connmark_dump of the component Netlink Message Handler. The manipulation of the argument opt with an unknown input leads to a uninitialized pointer vulnerability. The CWE definition for the vulnerability is CWE-824. The product accesses or uses a pointer that has not been initialized. As an impact it is known to affect confidentiality. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net: sched: act_connmark: initialize struct tc_ife to fix kernel leak In tcf_connmark_dump(), the variable 'opt' was partially initialized using a designatied initializer. While the padding bytes are reamined uninitialized. nla_put() copies the entire structure into a netlink message, these uninitialized bytes leaked to userspace. Initialize the structure with memset before assigning its fields to ensure all members and padding are cleared prior to beign copied.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2025-40279 since 04/16/2025. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 281777 (Amazon Linux 2 : kernel, --advisory ALAS2KERNEL-5.15-2025-096 (ALASKERNEL-5.15-2025-096)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.15.197, 6.1.159, 6.6.117, 6.12.59 or 6.17.9 eliminates this vulnerability. Applying the patch 218b67c8c8246d47a2a7910eae80abe4861fe2b7/73cc56c608c209d3d666cc571293b090a471da70/31e4aa93e2e5b5647fc235b0f6ee329646878f9e/51cb05d4fd632596816ba44e882e84db9fb28a7e/25837889ec062f2b7618142cd80253dff3da5343/62b656e43eaeae445a39cd8021a4f47065af4389 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 databases at Tenable (281777), EUVD (EUVD-2025-201576) and CERT Bund (WID-SEC-2025-2756). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

Debian Linux
Red Hat Enterprise Linux
Oracle Linux
NetApp FAS
NetApp AFF
RESF Rocky Linux
Open Source Linux Kernel
Microsoft Azure Linux

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

Version

License

open-source

Website

Vendor: https://www.kernel.org/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.5
VulDB Meta Temp Score: 3.4

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Uninitialized pointer
CWE: CWE-824 / CWE-908
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒