CVE-2021-47394

{"id": "CVE-2021-47394", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 1.8}]}, "published": "2024-05-21T15:15:24.710", "references": [{"url": "https://git.kernel.org/stable/c/a499b03bf36b0c2e3b958a381d828678ab0ffc5e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/f65c73d3aabb87d4353e0bc4a718b5ae8c43fd04", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/a499b03bf36b0c2e3b958a381d828678ab0ffc5e", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/f65c73d3aabb87d4353e0bc4a718b5ae8c43fd04", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-416"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: unlink table before deleting it\n\nsyzbot reports following UAF:\nBUG: KASAN: use-after-free in memcmp+0x18f/0x1c0 lib/string.c:955\n nla_strcmp+0xf2/0x130 lib/nlattr.c:836\n nft_table_lookup.part.0+0x1a2/0x460 net/netfilter/nf_tables_api.c:570\n nft_table_lookup net/netfilter/nf_tables_api.c:4064 [inline]\n nf_tables_getset+0x1b3/0x860 net/netfilter/nf_tables_api.c:4064\n nfnetlink_rcv_msg+0x659/0x13f0 net/netfilter/nfnetlink.c:285\n netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504\n\nProblem is that all get operations are lockless, so the commit_mutex\nheld by nft_rcv_nl_event() isn't enough to stop a parallel GET request\nfrom doing read-accesses to the table object even after synchronize_rcu().\n\nTo avoid this, unlink the table first and store the table objects in\non-stack scratch space."}, {"lang": "es", "value": " En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: netfilter: nf_tables: desvincular la tabla antes de eliminarla syzbot informa de lo sigueinte. UAF: BUG: KASAN: use-after-free en memcmp+0x18f/0x1c0 lib/string.c:955 nla_strcmp+ 0xf2/0x130 lib/nlattr.c:836 nft_table_lookup.part.0+0x1a2/0x460 net/netfilter/nf_tables_api.c:570 nft_table_lookup net/netfilter/nf_tables_api.c:4064 [en l\u00ednea] nf_tables_getset+0x1b3/0x860 net /filtro de red/ nf_tables_api.c:4064 nfnetlink_rcv_msg+0x659/0x13f0 net/netfilter/nfnetlink.c:285 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504 El problema es que todas las operaciones de obtenci\u00f3n no tienen bloqueo, por lo que el commit_mutex mantenido por () no es suficiente para evitar que una solicitud GET paralela realice accesos de lectura al objeto de la tabla incluso despu\u00e9s de sincronizar_rcu(). Para evitar esto, primero desvincule la tabla y almacene los objetos de la tabla en el espacio temporal de la pila."}], "lastModified": "2025-02-03T16:11:30.727", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B57F1C37-D6F2-497E-A183-96EC9B5876E0", "versionEndExcluding": "5.14.10", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E46C74C6-B76B-4C94-A6A4-FD2FFF62D644"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "60134C3A-06E4-48C1-B04F-2903732A4E56"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0460DA88-8FE1-46A2-9DDA-1F1ABA552E71"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}