{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-47291", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-21T13:27:52.130Z", "datePublished": "2024-05-21T14:35:16.071Z", "dateUpdated": "2026-08-05T08:47:07.127Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:47:07.127Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fix another slab-out-of-bounds in fib6_nh_flush_exceptions\n\nWhile running the self-tests on a KASAN enabled kernel, I observed a\nslab-out-of-bounds splat very similar to the one reported in\ncommit 821bbf79fe46 (\"ipv6: Fix KASAN: slab-out-of-bounds Read in\n fib6_nh_flush_exceptions\").\n\nWe additionally need to take care of fib6_metrics initialization\nfailure when the caller provides an nh.\n\nThe fix is similar, explicitly free the route instead of calling\nfib6_info_release on a half-initialized object." } ], "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 - Triggered via local rtnetlink (RTM_NEWNEXTHOP then RTM_NEWROUTE with RTA_NH_ID and invalid RTA_METRICS) or ipv6 route ioctl, not by processing remote packets.\nAC:L - Reliably triggered with a crafted nexthop plus an IPv6 route using that nhid and invalid metrics (e.g. unknown congctl), as covered by the fib_nexthops selftest; no race or attacker-uncontrollable condition.\nPR:L - RTM_NEWROUTE/RTM_NEWNEXTHOP require CAP_NET_ADMIN via netlink_net_capable against the netns user_ns, which an unprivileged process obtains in a user+network namespace (unshare -Urn).\nUI:N - Exploitation needs only attacker-issued netlink messages; no victim action is required.\nS:U - Memory corruption stays within the host kernel authority; this is not a VM escape, IOMMU bypass, or other cross-boundary impact.\nC:H - fib6_nh_flush_exceptions performs a slab out-of-bounds read of adjacent heap when releasing a fib6_info allocated without an embedded fib6_nh, which can disclose or leverage neighboring object contents.\nI:H - fib6_nh_release continues from the OOB data into pointer writes, kfree/free_percpu, and fib_nh_common_release on the unallocated fib6_nh region, yielding heap free/write primitives under attacker-influenced adjacent slab layout.\nA:H - The OOB access and subsequent invalid frees/puts on garbage pointers can oops, panic, or otherwise crash the kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/route.c" ], "versions": [ { "version": "f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74", "lessThan": "830251361425c5be044db4d826aaf304ea3d14c6", "status": "affected", "versionType": "git" }, { "version": "f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74", "lessThan": "ce8fafb68051fba52546f8bbe8621f7641683680", "status": "affected", "versionType": "git" }, { "version": "f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74", "lessThan": "115784bcccf135c3a3548098153413d76f16aae0", "status": "affected", "versionType": "git" }, { "version": "f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74", "lessThan": "8fb4792f091e608a0a1d353dfdf07ef55a719db5", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/route.c" ], "versions": [ { "version": "5.3", "status": "affected" }, { "version": "0", "lessThan": "5.3", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.136", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.54", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.13.6", "lessThanOrEqual": "5.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.14", "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": "5.3", "versionEndExcluding": "5.4.136" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "5.10.54" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "5.13.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "5.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/830251361425c5be044db4d826aaf304ea3d14c6" }, { "url": "https://git.kernel.org/stable/c/ce8fafb68051fba52546f8bbe8621f7641683680" }, { "url": "https://git.kernel.org/stable/c/115784bcccf135c3a3548098153413d76f16aae0" }, { "url": "https://git.kernel.org/stable/c/8fb4792f091e608a0a1d353dfdf07ef55a719db5" } ], "title": "ipv6: fix another slab-out-of-bounds in fib6_nh_flush_exceptions", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:32:08.000Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/830251361425c5be044db4d826aaf304ea3d14c6", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/ce8fafb68051fba52546f8bbe8621f7641683680", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/115784bcccf135c3a3548098153413d76f16aae0", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/8fb4792f091e608a0a1d353dfdf07ef55a719db5", "tags": [ "x_transferred" ] } ] }, { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2024-08-19T18:51:27.837598Z", "id": "CVE-2021-47291", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-08-19T18:52:14.586Z" } } ] } }