{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-53566", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-10-04T15:14:15.924Z", "datePublished": "2025-10-04T15:17:08.598Z", "dateUpdated": "2026-08-05T09:14:52.185Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:14:52.185Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_set_rbtree: fix null deref on element insertion\n\nThere is no guarantee that rb_prev() will not return NULL in nft_rbtree_gc_elem():\n\ngeneral protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN\nKASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]\n nft_add_set_elem+0x14b0/0x2990\n nf_tables_newsetelem+0x528/0xb30\n\nFurthermore, there is a possible use-after-free while iterating,\n'node' can be free'd so we need to cache the next value to use." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable code is reached only through the nfnetlink/nftables netlink socket (NFT_MSG_NEWSETELEM), which requires local system access; there is no packet-processing path into nft_rbtree_gc_elem().\nAC:L - The attacker fully controls set contents, element timeouts, and insertion order, so making an expired element the leftmost rbtree node (rb_prev() == NULL) during the overlap walk is deterministic and needs no race or unpredictable memory layout.\nPR:L - Only CAP_NET_ADMIN in the network namespace is required, enforced via namespace-relative netlink_net_capable(), which any unprivileged user obtains with \"unshare -Urn\"; nftables and the rbtree set backend are fully netns-aware and autoloaded.\nUI:N - The attacker triggers the bug entirely from their own process by issuing netlink set-element operations; no victim action is involved.\nS:U - The corruption and crash occur within the kernel of the same host and security authority as the attacking task, with no crossing of a VM, IOMMU, or sandbox boundary.\nC:H - The fix addresses a use-after-free during the tree walk (an rb_erase()'d, RCU-freed element is re-entered via rb_next()), and a UAF/double-free of nft_rbtree_elem objects gives the attacker control over reclaimed slab contents and thus a kernel memory read primitive.\nI:H - Beyond the crash, rb_erase() is invoked on an unvalidated rbe_prev (NULL or a wrong still-active element) and on already-erased nodes, producing attacker-influenced rbtree pointer writes and double nft_set_elem_destroy() — a classic heap-corruption primitive usable for control-flow hijack.\nA:H - The documented and readily reproducible outcome is a general protection fault / null-ptr-deref oops inside nft_add_set_elem() while holding the rbtree write lock and nftables commit mutex, panicking the kernel or wedging the netfilter subsystem." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nft_set_rbtree.c" ], "versions": [ { "version": "7ab87a326f20c52ff4d9972052d085be951c704b", "lessThan": "b76db53ee8802ee5683f8cb401d7e2ec6f9b3d56", "status": "affected", "versionType": "git" }, { "version": "181859bdfb9734aca449512fccaee4cacce64aed", "lessThan": "899aa5638568abf5d69de7a7bb95e4615157375b", "status": "affected", "versionType": "git" }, { "version": "4aacf3d78424293e318c616016865380b37b9cc5", "lessThan": "3fa13203b6d90cc3a33af47b058739f92ab82eef", "status": "affected", "versionType": "git" }, { "version": "2bf1435fa19d2c58054391b3bba40d5510a5758c", "lessThan": "ec5caa765f7f6960011c919c9aeb1467940421f6", "status": "affected", "versionType": "git" }, { "version": "318cb24a4c3fce8140afaf84e4d45fcb76fb280b", "lessThan": "a836be60a3aabcedcd9c79f545d409ace1f20ba6", "status": "affected", "versionType": "git" }, { "version": "c9e6978e2725a7d4b6cd23b2facd3f11422c0643", "lessThan": "a337706c1fb35aac3f26b48aca80421bdbe1d33a", "status": "affected", "versionType": "git" }, { "version": "c9e6978e2725a7d4b6cd23b2facd3f11422c0643", "lessThan": "61ae320a29b0540c16931816299eb86bf2b66c08", "status": "affected", "versionType": "git" }, { "version": "5.10.166", "lessThan": "5.10.181", "status": "affected", "versionType": "semver" }, { "version": "5.15.91", "lessThan": "5.15.113", "status": "affected", "versionType": "semver" }, { "version": "6.1.9", "lessThan": "6.1.30", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nft_set_rbtree.c" ], "versions": [ { "version": "6.2", "status": "affected" }, { "version": "0", "lessThan": "6.2", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.181", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.113", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.30", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.3.4", "lessThanOrEqual": "6.3.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.4", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.166", "versionEndExcluding": "5.10.181" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.91", "versionEndExcluding": "5.15.113" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.9", "versionEndExcluding": "6.1.30" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.3.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.4" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/b76db53ee8802ee5683f8cb401d7e2ec6f9b3d56" }, { "url": "https://git.kernel.org/stable/c/899aa5638568abf5d69de7a7bb95e4615157375b" }, { "url": "https://git.kernel.org/stable/c/3fa13203b6d90cc3a33af47b058739f92ab82eef" }, { "url": "https://git.kernel.org/stable/c/ec5caa765f7f6960011c919c9aeb1467940421f6" }, { "url": "https://git.kernel.org/stable/c/a836be60a3aabcedcd9c79f545d409ace1f20ba6" }, { "url": "https://git.kernel.org/stable/c/a337706c1fb35aac3f26b48aca80421bdbe1d33a" }, { "url": "https://git.kernel.org/stable/c/61ae320a29b0540c16931816299eb86bf2b66c08" } ], "title": "netfilter: nft_set_rbtree: fix null deref on element insertion", "x_generator": { "engine": "bippy-1.2.0" } } } }