netfilter: socket: Lookup orig tuple for IPv6 SNAT

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2025-22021
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2025-04-16 11:15:42 UTC
Updated2026-07-30 06:22:03 UTC
DescriptionIn 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.

Risk And Classification

Primary CVSS: v3.1 5.5 MEDIUM from [email protected]

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Problem Types: NVD-CWE-noinfo

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary5.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary10CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
3.1CNADECLARED10CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected eb31628e37a0a4e01fffd79dcc7f815d2357f53a 6488b96a79a26e19100ad872622f04e93b638d7f git Not specified
CNA Linux Linux affected eb31628e37a0a4e01fffd79dcc7f815d2357f53a 58ab63d3ded2ca6141357a2b24eee8453d0f871d git Not specified
CNA Linux Linux affected eb31628e37a0a4e01fffd79dcc7f815d2357f53a 1ca2169cc19dca893c7aae6af122852097435d16 git Not specified
CNA Linux Linux affected eb31628e37a0a4e01fffd79dcc7f815d2357f53a 1ec43100f7123010730b7ddfc3d5c2eac19e70e7 git Not specified
CNA Linux Linux affected eb31628e37a0a4e01fffd79dcc7f815d2357f53a 5251041573850e5020cd447374e23010be698898 git Not specified
CNA Linux Linux affected eb31628e37a0a4e01fffd79dcc7f815d2357f53a 2bb139e483f8cbe488d19d8c1135ac3615e2668c git Not specified
CNA Linux Linux affected eb31628e37a0a4e01fffd79dcc7f815d2357f53a 41904cbb343d115931d6bf79aa2c815cac4ef72b git Not specified
CNA Linux Linux affected eb31628e37a0a4e01fffd79dcc7f815d2357f53a 221c27259324ec1404f028d4f5a0f2ae7f63ee23 git Not specified
CNA Linux Linux affected eb31628e37a0a4e01fffd79dcc7f815d2357f53a 932b32ffd7604fb00b5c57e239a3cc4d901ccf6e git Not specified
CNA Linux Linux affected 3.13 Not specified
CNA Linux Linux unaffected 3.13 semver Not specified
CNA Linux Linux unaffected 5.4.292 5.4.* semver Not specified
CNA Linux Linux unaffected 5.10.236 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.180 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.133 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.86 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.22 6.12.* semver Not specified
CNA Linux Linux unaffected 6.13.10 6.13.* semver Not specified
CNA Linux Linux unaffected 6.14.1 6.14.* semver Not specified
CNA Linux Linux unaffected 6.15 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
lists.debian.org/debian-lts-announce/2025/05/msg00030.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org
git.kernel.org/stable/c/5251041573850e5020cd447374e23010be698898 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/41904cbb343d115931d6bf79aa2c815cac4ef72b 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/1ec43100f7123010730b7ddfc3d5c2eac19e70e7 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/2bb139e483f8cbe488d19d8c1135ac3615e2668c 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/1ca2169cc19dca893c7aae6af122852097435d16 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/6488b96a79a26e19100ad872622f04e93b638d7f 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/58ab63d3ded2ca6141357a2b24eee8453d0f871d 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/221c27259324ec1404f028d4f5a0f2ae7f63ee23 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
lists.debian.org/debian-lts-announce/2025/05/msg00045.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org
git.kernel.org/stable/c/932b32ffd7604fb00b5c57e239a3cc4d901ccf6e 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report