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netfilter: socket: Lookup orig tuple for IPv6 SNAT

Type: advisorySource: Official CVE List1 source record

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.

Announced Source revision 1
Original source ↗

CVE-2025-22021

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2025-22021

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "eb31628e37a0a4e01fffd79dcc7f815d2357f53a",
        "lessThan": "6488b96a79a26e19100ad872622f04e93b638d7f",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "eb31628e37a0a4e01fffd79dcc7f815d2357f53a",
        "lessThan": "58ab63d3ded2ca6141357a2b24eee8453d0f871d",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "eb31628e37a0a4e01fffd79dcc7f815d2357f53a",
        "lessThan": "1ca2169cc19dca893c7aae6af122852097435d16",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "eb31628e37a0a4e01fffd79dcc7f815d2357f53a",
        "lessThan": "1ec43100f7123010730b7ddfc3d5c2eac19e70e7",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "eb31628e37a0a4e01fffd79dcc7f815d2357f53a",
        "lessThan": "5251041573850e5020cd447374e23010be698898",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "eb31628e37a0a4e01fffd79dcc7f815d2357f53a",
        "lessThan": "2bb139e483f8cbe488d19d8c1135ac3615e2668c",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "eb31628e37a0a4e01fffd79dcc7f815d2357f53a",
        "lessThan": "41904cbb343d115931d6bf79aa2c815cac4ef72b",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "eb31628e37a0a4e01fffd79dcc7f815d2357f53a",
        "lessThan": "221c27259324ec1404f028d4f5a0f2ae7f63ee23",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "eb31628e37a0a4e01fffd79dcc7f815d2357f53a",
        "lessThan": "932b32ffd7604fb00b5c57e239a3cc4d901ccf6e",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "net/ipv6/netfilter/nf_socket_ipv6.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "3.13"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "3.13",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.4.292",
        "versionType": "semver",
        "lessThanOrEqual": "5.4.*"
      },
      {
        "status": "unaffected",
        "version": "5.10.236",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.180",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.133",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.86",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.22",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.13.10",
        "versionType": "semver",
        "lessThanOrEqual": "6.13.*"
      },
      {
        "status": "unaffected",
        "version": "6.14.1",
        "versionType": "semver",
        "lessThanOrEqual": "6.14.*"
      },
      {
        "status": "unaffected",
        "version": "6.15",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "net/ipv6/netfilter/nf_socket_ipv6.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2025-22021

Source reference: /cveMetadata/cveId

Publisher severity

critical

Source reference: /containers/cna/metrics

Event
#30453 · Revision 1
Added to Heist Feed
Publisher date
Read the original announcement