{"cve":"CVE-2021-47397","nvd":{"published":"2024-05-21T15:15:25.017","modified":"2026-08-04T10:17:01.747","status":"Modified","description":"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  <IRQ>\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","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/77bc7dcf0fcc1519341a91788d7a2914fcfddf6d","https://git.kernel.org/stable/c/8180611c238e11676612eb2a9828b1c7a3a4d77b","https://git.kernel.org/stable/c/8c630a7b4f9dec63f08bd881ab77984a724a5124","https://git.kernel.org/stable/c/9c6591ae8e63f93c895ad5e2703c36c548aac997","https://git.kernel.org/stable/c/ec018021cf445abbe8e2f3e2a7f1dcc813cb8ea1"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47397","score":0.00776,"percentile":0.55802,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}