CVE - CVE-2025-22021

CVE-ID
CVE-2025-22021	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
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.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://git.kernel.org/stable/c/1ca2169cc19dca893c7aae6af122852097435d16 URL:https://git.kernel.org/stable/c/1ca2169cc19dca893c7aae6af122852097435d16 MISC:https://git.kernel.org/stable/c/1ec43100f7123010730b7ddfc3d5c2eac19e70e7 URL:https://git.kernel.org/stable/c/1ec43100f7123010730b7ddfc3d5c2eac19e70e7 MISC:https://git.kernel.org/stable/c/221c27259324ec1404f028d4f5a0f2ae7f63ee23 URL:https://git.kernel.org/stable/c/221c27259324ec1404f028d4f5a0f2ae7f63ee23 MISC:https://git.kernel.org/stable/c/2bb139e483f8cbe488d19d8c1135ac3615e2668c URL:https://git.kernel.org/stable/c/2bb139e483f8cbe488d19d8c1135ac3615e2668c MISC:https://git.kernel.org/stable/c/41904cbb343d115931d6bf79aa2c815cac4ef72b URL:https://git.kernel.org/stable/c/41904cbb343d115931d6bf79aa2c815cac4ef72b MISC:https://git.kernel.org/stable/c/5251041573850e5020cd447374e23010be698898 URL:https://git.kernel.org/stable/c/5251041573850e5020cd447374e23010be698898 MISC:https://git.kernel.org/stable/c/58ab63d3ded2ca6141357a2b24eee8453d0f871d URL:https://git.kernel.org/stable/c/58ab63d3ded2ca6141357a2b24eee8453d0f871d MISC:https://git.kernel.org/stable/c/6488b96a79a26e19100ad872622f04e93b638d7f URL:https://git.kernel.org/stable/c/6488b96a79a26e19100ad872622f04e93b638d7f MISC:https://git.kernel.org/stable/c/932b32ffd7604fb00b5c57e239a3cc4d901ccf6e URL:https://git.kernel.org/stable/c/932b32ffd7604fb00b5c57e239a3cc4d901ccf6e
Assigning CNA
kernel.org
Date Record Created
20241229	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20241229)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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