{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-47316", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-21T14:28:16.973Z", "datePublished": "2024-05-21T14:35:32.564Z", "dateUpdated": "2026-08-05T08:47:14.619Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:47:14.619Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix NULL dereference in nfs3svc_encode_getaclres\n\nIn error cases the dentry may be NULL.\n\nBefore 20798dfe249a, the encoder also checked dentry and\nd_really_is_positive(dentry), but that looks like overkill to me--zero\nstatus should be enough to guarantee a positive dentry.\n\nThis isn't the first time we've seen an error-case NULL dereference\nhidden in the initialization of a local variable in an xdr encoder. But\nI went back through the other recent rewrites and didn't spot any\nsimilar bugs." } ], "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 nfsd's NFSv3 ACL program (NFS_ACL_PROGRAM) GETACL result encoder, reached by sending RPC requests over the network to the in-kernel NFS server (TCP/UDP, typically port 2049).\nAC:L - An attacker reliably triggers the crash by sending a GETACL with a malformed or invalid filehandle so fh_verify fails and fh_dentry stays NULL; no race or attacker-uncontrollable condition is required.\nPR:N - The path is reachable with AUTH_NULL or forgeable AUTH_UNIX after only IP-based export matching, before any meaningful credential verification or valid filehandle access, matching other nfsd pre-auth/network DoS scores.\nUI:N - Exploitation requires only attacker-sent NFSACL GETACL RPCs; no victim user action is needed.\nS:U - Impact is confined to the NFS server host kernel; there is no VM escape, IOMMU bypass, or other cross-authority boundary crossing.\nC:N - This is a pure NULL pointer dereference of dentry->d_inode with no out-of-bounds read, UAF, or other information-disclosure primitive.\nI:N - The bug only crashes on NULL dereference in the encoder; it does not corrupt memory or provide a write/code-execution primitive.\nA:H - d_inode(NULL) causes a kernel oops/panic in nfsd, fully disrupting the NFS server and host availability, and can be repeated at will." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfsd/nfs3acl.c" ], "versions": [ { "version": "d505e66191072748620fc0af038cea4e4da0e3cd", "lessThan": "e79057d15d96ef19de4de6d7e479bae3d58a2a8d", "status": "affected", "versionType": "git" }, { "version": "20798dfe249a01ad1b12eec7dbc572db5003244a", "lessThan": "650e6f383a6eb40f7c0a010982a74ab4b6893870", "status": "affected", "versionType": "git" }, { "version": "20798dfe249a01ad1b12eec7dbc572db5003244a", "lessThan": "ab1016d39cc052064e32f25ad18ef8767a0ee3b8", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfsd/nfs3acl.c" ], "versions": [ { "version": "5.13", "status": "affected" }, { "version": "0", "lessThan": "5.13", "status": "unaffected", "versionType": "semver" }, { "version": "5.13.4", "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": "5.13", "versionEndExcluding": "5.13.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "5.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/e79057d15d96ef19de4de6d7e479bae3d58a2a8d" }, { "url": "https://git.kernel.org/stable/c/650e6f383a6eb40f7c0a010982a74ab4b6893870" }, { "url": "https://git.kernel.org/stable/c/ab1016d39cc052064e32f25ad18ef8767a0ee3b8" } ], "title": "nfsd: fix NULL dereference in nfs3svc_encode_getaclres", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CISA ADP Vulnrichment", "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2021-47316", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-05-21T18:45:04.809482Z" } } } ], "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-04T17:13:36.645Z" } }, { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:32:08.599Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/e79057d15d96ef19de4de6d7e479bae3d58a2a8d", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/650e6f383a6eb40f7c0a010982a74ab4b6893870", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/ab1016d39cc052064e32f25ad18ef8767a0ee3b8", "tags": [ "x_transferred" ] } ] }, { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-05-12T10:12:23.647Z" }, "affected": [ { "vendor": "Siemens", "product": "RUGGEDCOM RST2428P", "versions": [ { "status": "unaffected", "version": "0", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family", "versions": [ { "status": "unaffected", "version": "0", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SCALANCE XCM-/XRM-/XCH-/XRH-300 family", "versions": [ { "status": "unaffected", "version": "0", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "versions": [ { "status": "affected", "version": "0", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-265688.html" }, { "url": "https://cert-portal.siemens.com/productcert/html/ssa-355557.html" } ] } ] } }