Linux Kernel up to 6.17.2 ipvs __ip_vs_ftp_exit use after free

CVSS Meta Temp Score
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CTI Interest Score
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7.6$0-$5k0.00

Summaryinfo

A vulnerability has been found in Linux Kernel up to 5.15.194/6.1.155/6.6.111/6.12.52/6.17.2 and classified as critical. This issue affects the function __ip_vs_ftp_exit of the component ipvs. This manipulation causes use after free. This vulnerability appears as CVE-2025-40018. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 5.15.194/6.1.155/6.6.111/6.12.52/6.17.2 and classified as critical. Affected by this vulnerability is the function __ip_vs_ftp_exit of the component ipvs. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: ipvs: Defer ip_vs_ftp unregister during netns cleanup On the netns cleanup path, __ip_vs_ftp_exit() may unregister ip_vs_ftp before connections with valid cp->app pointers are flushed, leading to a use-after-free. Fix this by introducing a global `exiting_module` flag, set to true in ip_vs_ftp_exit() before unregistering the pernet subsystem. In __ip_vs_ftp_exit(), skip ip_vs_ftp unregister if called during netns cleanup (when exiting_module is false) and defer it to __ip_vs_cleanup_batch(), which unregisters all apps after all connections are flushed. If called during module exit, unregister ip_vs_ftp immediately.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2025-40018 since 04/16/2025. The exploitation appears to be easy. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 02/02/2026).

The vulnerability scanner Nessus provides a plugin with the ID 271715 (Linux Distros Unpatched Vulnerability : CVE-2025-40018), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.15.195, 6.1.156, 6.6.112, 6.12.53, 6.17.3 or 6.18-rc1 eliminates this vulnerability. Applying the patch 1d79471414d7b9424d699afff2aa79fff322f52d/53717f8a4347b78eac6488072ad8e5adbaff38d9/8cbe2a21d85727b66d7c591fd5d83df0d8c4f757/dc1a481359a72ee7e548f1f5da671282a7c13b8f/a343811ef138a265407167294275201621e9ebb2/134121bfd99a06d44ef5ba15a9beb075297c0821 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 (271715) and CERT Bund (WID-SEC-2025-2407). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Debian Linux
  • Google Cloud Platform
  • Amazon Linux 2
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel
  • Dell NetWorker

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.6

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
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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Nessus ID: 271715
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-40018

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.15.195/6.1.156/6.6.112/6.12.53/6.17.3/6.18-rc1
Patch: 1d79471414d7b9424d699afff2aa79fff322f52d/53717f8a4347b78eac6488072ad8e5adbaff38d9/8cbe2a21d85727b66d7c591fd5d83df0d8c4f757/dc1a481359a72ee7e548f1f5da671282a7c13b8f/a343811ef138a265407167294275201621e9ebb2/134121bfd99a06d44ef5ba15a9beb075297c0821

Timelineinfo

04/16/2025 CVE reserved
10/24/2025 +191 days Advisory disclosed
10/24/2025 +0 days VulDB entry created
02/02/2026 +101 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-40018 (🔒)
GCVE (CVE): GCVE-0-2025-40018
GCVE (VulDB): GCVE-100-329773
CERT Bund: WID-SEC-2025-2407 - Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 10/24/2025 15:27
Updated: 02/02/2026 10:43
Changes: 10/24/2025 15:27 (59), 10/28/2025 09:54 (7), 10/28/2025 16:17 (2), 12/09/2025 10:18 (1), 02/02/2026 10:43 (1)
Complete: 🔍
Cache ID: 216::103

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