{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-47397", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-21T14:58:30.815Z", "datePublished": "2024-05-21T15:03:53.431Z", "dateUpdated": "2026-08-05T08:47:38.908Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:47:38.908Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb\n\nWe should always check if skb_header_pointer's return is NULL before\nusing it, otherwise it may cause null-ptr-deref, as syzbot reported:\n\n KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\n RIP: 0010:sctp_rcv_ootb net/sctp/input.c:705 [inline]\n RIP: 0010:sctp_rcv+0x1d84/0x3220 net/sctp/input.c:196\n Call Trace:\n \n sctp6_rcv+0x38/0x60 net/sctp/ipv6.c:1109\n ip6_protocol_deliver_rcu+0x2e9/0x1ca0 net/ipv6/ip6_input.c:422\n ip6_input_finish+0x62/0x170 net/ipv6/ip6_input.c:463\n NF_HOOK include/linux/netfilter.h:307 [inline]\n NF_HOOK include/linux/netfilter.h:301 [inline]\n ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:472\n dst_input include/net/dst.h:460 [inline]\n ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]\n NF_HOOK include/linux/netfilter.h:307 [inline]\n NF_HOOK include/linux/netfilter.h:301 [inline]\n ipv6_rcv+0x28c/0x3c0 net/ipv6/ip6_input.c:297" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The bug is in sctp_rcv_ootb(), reached from sctp4_rcv/sctp6_rcv on the IPPROTO_SCTP receive path when processing out-of-the-blue packets; a remote peer can deliver crafted SCTP packets over IPv4/IPv6 with no local socket required beyond the SCTP stack being loaded.\nAC:L - The attacker only needs to send crafted SCTP packets that fail association lookup and enter the OOTB walker; there is no race, victim-side state, or other condition outside the attacker’s control required to hit the unchecked skb_header_pointer() result.\nPR:N - OOTB handling runs for packets that match no association, falls back to the per-net ctl_sock endpoint, and requires no authentication or privileges on the target.\nUI:N - Exploitation requires only sending network packets; no user action such as opening a file or establishing an application session is needed.\nS:U - Impact is confined to the vulnerable host’s kernel (crash/DoS); this does not cross a VM, IOMMU, or other security authority boundary.\nC:N - The defect is a pure NULL pointer dereference of skb_header_pointer()’s return value when reading ch->length; it does not disclose kernel memory.\nI:N - There is no write, type confusion, or other memory corruption primitive—only a NULL deref—so integrity cannot be compromised beyond the crash itself.\nA:H - Dereferencing the NULL chunk header pointer causes a kernel oops/general protection fault in softirq/IRQ receive context, which is a full availability impact and can be repeated with further packets." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sctp/input.c" ], "versions": [ { "version": "3acb50c18d8d6650f10919464ade4dcdaf41d62f", "lessThan": "77bc7dcf0fcc1519341a91788d7a2914fcfddf6d", "status": "affected", "versionType": "git" }, { "version": "3acb50c18d8d6650f10919464ade4dcdaf41d62f", "lessThan": "8c630a7b4f9dec63f08bd881ab77984a724a5124", "status": "affected", "versionType": "git" }, { "version": "3acb50c18d8d6650f10919464ade4dcdaf41d62f", "lessThan": "ec018021cf445abbe8e2f3e2a7f1dcc813cb8ea1", "status": "affected", "versionType": "git" }, { "version": "3acb50c18d8d6650f10919464ade4dcdaf41d62f", "lessThan": "9c6591ae8e63f93c895ad5e2703c36c548aac997", "status": "affected", "versionType": "git" }, { "version": "3acb50c18d8d6650f10919464ade4dcdaf41d62f", "lessThan": "8180611c238e11676612eb2a9828b1c7a3a4d77b", "status": "affected", "versionType": "git" }, { "version": "3acb50c18d8d6650f10919464ade4dcdaf41d62f", "lessThan": "f7e745f8e94492a8ac0b0a26e25f2b19d342918f", "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/sctp/input.c" ], "versions": [ { "version": "4.8", "status": "affected" }, { "version": "0", "lessThan": "4.8", "status": "unaffected", "versionType": "semver" }, { "version": "4.14.249", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.209", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.151", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.71", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.14.10", "lessThanOrEqual": "5.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15", "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": "4.8", "versionEndExcluding": "4.14.249" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "4.19.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "5.4.151" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "5.10.71" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "5.14.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "5.15" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/77bc7dcf0fcc1519341a91788d7a2914fcfddf6d" }, { "url": "https://git.kernel.org/stable/c/8c630a7b4f9dec63f08bd881ab77984a724a5124" }, { "url": "https://git.kernel.org/stable/c/ec018021cf445abbe8e2f3e2a7f1dcc813cb8ea1" }, { "url": "https://git.kernel.org/stable/c/9c6591ae8e63f93c895ad5e2703c36c548aac997" }, { "url": "https://git.kernel.org/stable/c/8180611c238e11676612eb2a9828b1c7a3a4d77b" }, { "url": "https://git.kernel.org/stable/c/f7e745f8e94492a8ac0b0a26e25f2b19d342918f" } ], "title": "sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:39:59.634Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/77bc7dcf0fcc1519341a91788d7a2914fcfddf6d", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/8c630a7b4f9dec63f08bd881ab77984a724a5124", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/ec018021cf445abbe8e2f3e2a7f1dcc813cb8ea1", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/9c6591ae8e63f93c895ad5e2703c36c548aac997", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/8180611c238e11676612eb2a9828b1c7a3a4d77b", "tags": [ "x_transferred" ] }, { "url": 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