{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2022-49561", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-02-26T02:08:31.591Z", "datePublished": "2025-02-26T02:14:06.030Z", "dateUpdated": "2026-08-05T08:55:45.099Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:55:45.099Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: conntrack: re-fetch conntrack after insertion\n\nIn case the conntrack is clashing, insertion can free skb->_nfct and\nset skb->_nfct to the already-confirmed entry.\n\nThis wasn't found before because the conntrack entry and the extension\nspace used to free'd after an rcu grace period, plus the race needs\nevents enabled to trigger." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The UAF sits in nf_conntrack_confirm(), invoked from nf_confirm on NF_INET_LOCAL_IN and NF_INET_POST_ROUTING for packets traversing conntrack. On firewalls, NAT gateways, Docker/K8s hosts, and internet-facing servers with stateful filtering, a remote peer’s packets reach this path with no local login.\nAC:L - The insertion clash is triggered by concurrent UDP (allow_clash) flows that the attacker can send themselves, so they control both sides of the race. Conntrack event/ecache support is common in real deployments; it is not a rare uncontrollable condition.\nPR:N - Exploitation uses unauthenticated network packets against an already-active conntrack data path. No credentials or CAP_NET_ADMIN are required on the attacker side once the victim system is tracking connections.\nUI:N - The attacker only needs to send crafted concurrent packets; no victim user action such as mounting a device or opening a file is required.\nS:U - Impact is memory corruption within the host kernel’s conntrack authority. This is standard local kernel compromise, not a VM/IOMMU/sandbox boundary crossing.\nC:H - Clash resolution can nf_ct_put()/free the loser ct and immediately kfree its extension, then nf_ct_ecache_exist/nf_ct_deliver_cached_events reuse that pointer—a use-after-free that can yield arbitrary read primitives.\nI:H - The same UAF on the nf_conn/extension heap is exploitable for heap reuse and arbitrary write/control-flow hijacking under standard kernel UAF exploitation.\nA:H - Dereferencing the freed conntrack/ecache state can oops/panic the kernel, and UAFs are treated as high availability impact even when not fully turned into code execution." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/netfilter/nf_conntrack_core.h" ], "versions": [ { "version": "71d8c47fc653711c41bc3282e5b0e605b3727956", "lessThan": "e97222b785e70e8973281666d709baad6523d8af", "status": "affected", "versionType": "git" }, { "version": "71d8c47fc653711c41bc3282e5b0e605b3727956", "lessThan": "92a999d1963eed0df666284e20055136ceabd12f", "status": "affected", "versionType": "git" }, { "version": "71d8c47fc653711c41bc3282e5b0e605b3727956", "lessThan": "b16bb373988da3ceb0308381634117e18b6ec60d", "status": "affected", "versionType": "git" }, { "version": "71d8c47fc653711c41bc3282e5b0e605b3727956", "lessThan": "91a36ec160ec1a0c8f5352b772dffcbb0b6023e3", "status": "affected", "versionType": "git" }, { "version": "71d8c47fc653711c41bc3282e5b0e605b3727956", "lessThan": "01989d7eebb61c99bd4b88ebc8e261bd2f02caed", "status": "affected", "versionType": "git" }, { "version": "71d8c47fc653711c41bc3282e5b0e605b3727956", "lessThan": "04f9e9104c969d8ce10a4a43634f641ed082092d", "status": "affected", "versionType": "git" }, { "version": "71d8c47fc653711c41bc3282e5b0e605b3727956", "lessThan": "04e4a11dc723c52db7a36dc58f0d69ce6426f8f0", "status": "affected", "versionType": "git" }, { "version": "71d8c47fc653711c41bc3282e5b0e605b3727956", "lessThan": "56b14ecec97f39118bf85c9ac2438c5a949509ed", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/netfilter/nf_conntrack_core.h" ], "versions": [ { "version": "4.7", "status": "affected" }, { "version": "0", "lessThan": "4.7", "status": "unaffected", "versionType": "semver" }, { "version": "4.14.282", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.246", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.197", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.120", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.45", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.17.13", "lessThanOrEqual": "5.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.18.2", "lessThanOrEqual": "5.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.19", "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": "4.7", "versionEndExcluding": "4.14.282" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "4.19.246" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "5.4.197" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "5.10.120" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "5.15.45" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "5.17.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "5.18.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "5.19" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/e97222b785e70e8973281666d709baad6523d8af" }, { "url": "https://git.kernel.org/stable/c/92a999d1963eed0df666284e20055136ceabd12f" }, { "url": "https://git.kernel.org/stable/c/b16bb373988da3ceb0308381634117e18b6ec60d" }, { "url": "https://git.kernel.org/stable/c/91a36ec160ec1a0c8f5352b772dffcbb0b6023e3" }, { "url": "https://git.kernel.org/stable/c/01989d7eebb61c99bd4b88ebc8e261bd2f02caed" }, { "url": "https://git.kernel.org/stable/c/04f9e9104c969d8ce10a4a43634f641ed082092d" }, { "url": "https://git.kernel.org/stable/c/04e4a11dc723c52db7a36dc58f0d69ce6426f8f0" }, { "url": "https://git.kernel.org/stable/c/56b14ecec97f39118bf85c9ac2438c5a949509ed" } ], "title": "netfilter: conntrack: re-fetch conntrack after insertion", "x_generator": { "engine": "bippy-1.2.0" } } } }