{"cve":"CVE-2021-47068","nvd":{"published":"2024-02-29T23:15:08.170","modified":"2026-06-17T04:16:22.493","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/nfc: fix use-after-free llcp_sock_bind/connect\n\nCommits 8a4cd82d (\"nfc: fix refcount leak in llcp_sock_connect()\")\nand c33b1cc62 (\"nfc: fix refcount leak in llcp_sock_bind()\")\nfixed a refcount leak bug in bind/connect but introduced a\nuse-after-free if the same local is assigned to 2 different sockets.\n\nThis can be triggered by the following simple program:\n    int sock1 = socket( AF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP );\n    int sock2 = socket( AF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP );\n    memset( &addr, 0, sizeof(struct sockaddr_nfc_llcp) );\n    addr.sa_family = AF_NFC;\n    addr.nfc_protocol = NFC_PROTO_NFC_DEP;\n    bind( sock1, (struct sockaddr*) &addr, sizeof(struct sockaddr_nfc_llcp) )\n    bind( sock2, (struct sockaddr*) &addr, sizeof(struct sockaddr_nfc_llcp) )\n    close(sock1);\n    close(sock2);\n\nFix this by assigning NULL to llcp_sock->local after calling\nnfc_llcp_local_put.\n\nThis addresses CVE-2021-23134.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/18175fe17ae043a0b81e5d511f8817825784c299","https://git.kernel.org/stable/c/18ae4a192a4496e48a5490b52812645d2413307c","https://git.kernel.org/stable/c/26157c82ba756767b2bd66d28a71b1bc454447f6","https://git.kernel.org/stable/c/374cdde4dcc9c909a60713abdbbf96d5e3e09f91","https://git.kernel.org/stable/c/48fba458fe54cc2a980a05c13e6c19b8b2cfb610"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:46:54.846886191+00:00"},"epss":{"cve":"CVE-2021-47068","score":0.00233,"percentile":0.14186,"date":"2026-11-01"},"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."]}