{"uuid": "6764f8bd-9cf9-4e70-816b-3dbc33d5632f", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "2a075640-a300-48a4-bb44-bc6130783b9b", "vulnerability": "CVE-2025-22021", "type": "published-proof-of-concept", "source": "https://t.me/DarkWebInformer_CVEAlerts/12009", "content": "\ud83d\udd17 DarkWebInformer.com - Cyber Threat Intelligence\n\ud83d\udccc CVE ID: CVE-2025-22021\n\ud83d\udd25 CVSS Score: N/A\n\ud83d\udd39 Description: In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: socket: Lookup orig tuple for IPv6 SNAT\n\nnf_sk_lookup_slow_v4 does the conntrack lookup for IPv4 packets to\nrestore the original 5-tuple in case of SNAT, to be able to find the\nright socket (if any). Then socket_match() can correctly check whether\nthe socket was transparent.\n\nHowever, the IPv6 counterpart (nf_sk_lookup_slow_v6) lacks this\nconntrack lookup, making xt_socket fail to match on the socket when the\npacket was SNATed. Add the same logic to nf_sk_lookup_slow_v6.\n\nIPv6 SNAT is used in Kubernetes clusters for pod-to-world packets, as\npods' addresses are in the fd00::/8 ULA subnet and need to be replaced\nwith the node's external address. Cilium leverages Envoy to enforce L7\npolicies, and Envoy uses transparent sockets. Cilium inserts an iptables\nprerouting rule that matches on `-m socket --transparent` and redirects\nthe packets to localhost, but it fails to match SNATed IPv6 packets due\nto that missing conntrack lookup.\n\ud83d\udccf Published: 2025-04-16T10:20:37.695Z\n\ud83d\udccf Modified: 2025-04-16T10:20:37.695Z\n\ud83d\udd17 References:\n1. https://git.kernel.org/stable/c/6488b96a79a26e19100ad872622f04e93b638d7f\n2. https://git.kernel.org/stable/c/58ab63d3ded2ca6141357a2b24eee8453d0f871d\n3. https://git.kernel.org/stable/c/1ca2169cc19dca893c7aae6af122852097435d16\n4. https://git.kernel.org/stable/c/1ec43100f7123010730b7ddfc3d5c2eac19e70e7\n5. https://git.kernel.org/stable/c/5251041573850e5020cd447374e23010be698898\n6. https://git.kernel.org/stable/c/2bb139e483f8cbe488d19d8c1135ac3615e2668c\n7. https://git.kernel.org/stable/c/41904cbb343d115931d6bf79aa2c815cac4ef72b\n8. https://git.kernel.org/stable/c/221c27259324ec1404f028d4f5a0f2ae7f63ee23\n9. https://git.kernel.org/stable/c/932b32ffd7604fb00b5c57e239a3cc4d901ccf6e", "creation_timestamp": "2025-04-16T10:55:55.000000Z"}