Linux Kernel up to 6.14.0 netfilter nf_sk_lookup_slow_v4 privilege escalation

CVSS Meta Temp Score
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CTI Interest Score
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5.4$0-$5k0.00

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.14.0 and classified as problematic. The impacted element is the function nf_sk_lookup_slow_v4 of the component netfilter. This manipulation causes an unknown weakness. This vulnerability appears as CVE-2025-22021. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic was found in Linux Kernel up to 6.14.0. Affected by this vulnerability is the function nf_sk_lookup_slow_v4 of the component netfilter. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: netfilter: socket: Lookup orig tuple for IPv6 SNAT nf_sk_lookup_slow_v4 does the conntrack lookup for IPv4 packets to restore the original 5-tuple in case of SNAT, to be able to find the right socket (if any). Then socket_match() can correctly check whether the socket was transparent. However, the IPv6 counterpart (nf_sk_lookup_slow_v6) lacks this conntrack lookup, making xt_socket fail to match on the socket when the packet was SNATed. Add the same logic to nf_sk_lookup_slow_v6. IPv6 SNAT is used in Kubernetes clusters for pod-to-world packets, as pods' addresses are in the fd00::/8 ULA subnet and need to be replaced with the node's external address. Cilium leverages Envoy to enforce L7 policies, and Envoy uses transparent sockets. Cilium inserts an iptables prerouting rule that matches on `-m socket --transparent` and redirects the packets to localhost, but it fails to match SNATed IPv6 packets due to that missing conntrack lookup.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2025-22021 since 12/29/2024. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 237255 (Debian dla-4178 : ata-modules-5.10.0-34-armmp-di - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.292, 5.10.236, 5.15.180, 6.1.133, 6.6.86, 6.12.22, 6.13.10, 6.14.1 or 6.15-rc1 eliminates this vulnerability. Applying the patch 6488b96a79a26e19100ad872622f04e93b638d7f/58ab63d3ded2ca6141357a2b24eee8453d0f871d/1ca2169cc19dca893c7aae6af122852097435d16/1ec43100f7123010730b7ddfc3d5c2eac19e70e7/5251041573850e5020cd447374e23010be698898/2bb139e483f8cbe488d19d8c1135ac3615e2668c/41904cbb343d115931d6bf79aa2c815cac4ef72b/221c27259324ec1404f028d4f5a0f2ae7f63ee23/932b32ffd7604fb00b5c57e239a3cc4d901ccf6e 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 (237255) and CERT Bund (WID-SEC-2025-0837). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

  • Debian Linux
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • RESF Rocky Linux
  • Dell Avamar
  • Open Source Linux Kernel
  • Dell NetWorker
  • Dell Secure Connect Gateway

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.4

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CVSSv2info

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

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 237255
Nessus Name: Debian dla-4178 : ata-modules-5.10.0-34-armmp-di - security update

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 5.4.292/5.10.236/5.15.180/6.1.133/6.6.86/6.12.22/6.13.10/6.14.1/6.15-rc1
Patch: 6488b96a79a26e19100ad872622f04e93b638d7f/58ab63d3ded2ca6141357a2b24eee8453d0f871d/1ca2169cc19dca893c7aae6af122852097435d16/1ec43100f7123010730b7ddfc3d5c2eac19e70e7/5251041573850e5020cd447374e23010be698898/2bb139e483f8cbe488d19d8c1135ac3615e2668c/41904cbb343d115931d6bf79aa2c815cac4ef72b/221c27259324ec1404f028d4f5a0f2ae7f63ee23/932b32ffd7604fb00b5c57e239a3cc4d901ccf6e

Timelineinfo

12/29/2024 🔍
04/16/2025 +107 days 🔍
04/16/2025 +0 days 🔍
02/10/2026 +300 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-22021 (🔍)
GCVE (CVE): GCVE-0-2025-22021
GCVE (VulDB): GCVE-100-304993
CERT Bund: WID-SEC-2025-0837 - Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 04/16/2025 13:15
Updated: 02/10/2026 10:41
Changes: 04/16/2025 13:15 (57), 05/27/2025 05:00 (2), 07/20/2025 16:13 (7), 10/23/2025 11:10 (1), 10/28/2025 23:34 (11), 02/10/2026 10:41 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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