{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-47168", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-03-25T09:12:14.111Z", "datePublished": "2024-03-25T09:16:20.778Z", "dateUpdated": "2026-08-05T08:46:28.312Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:46:28.312Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: fix an incorrect limit in filelayout_decode_layout()\n\nThe \"sizeof(struct nfs_fh)\" is two bytes too large and could lead to\nmemory corruption. It should be NFS_MAXFHSIZE because that's the size\nof the ->data[] buffer.\n\nI reversed the size of the arguments to put the variable on the left." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The bug is reached when the NFSv4.1 pNFS filelayout client parses a LAYOUTGET layout blob from a remote metadata server over NFS/RPC; a malicious or compromised MDS (or MITM) delivers the oversized filehandle over the network.\nAC:L - The attacker fully controls the LAYOUTGET XDR and can set fh size to 129–130 to pass the incorrect sizeof check and deterministically overflow; no race or special victim-side memory layout is required.\nPR:N - Exploitation requires no privileges on the victim client—the attacker only needs to be (or impersonate) the NFS metadata server sending protocol responses after a normal pNFS mount/session.\nUI:N - In the highest-impact deployment—an already-mounted enterprise/HPC/cloud pNFS share (fstab/autofs)—routine file I/O or LAYOUTGET-on-OPEN triggers the decode path with no further interactive victim action.\nS:U - The heap overflow corrupts memory only within the client kernel’s security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - This is attacker-controlled heap memory corruption (OOB write of up to two bytes past the allocated nfs_fh, with oversized fh->size reused on later encode/copy paths), which can be leveraged for kernel information disclosure.\nI:H - The out-of-bounds write into the heap-allocated nfs_fh object is memory corruption suitable for adjacent-object/control-flow primitives; the same class of 1–2 byte NFS fh overflow (CVE-2021-4157) was assessed as privilege-escalation capable.\nA:H - Heap corruption in kernel context can cause oops/panic (and is reliably fatal under KASAN/debug allocators), fully denying availability of the client host." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfs/filelayout/filelayout.c" ], "versions": [ { "version": "16b374ca439fb406e46e071f75428f5b033056f8", "lessThan": "9d280ab53df1d4a1043bd7a9e7c6a2f9cfbfe040", "status": "affected", "versionType": "git" }, { "version": "16b374ca439fb406e46e071f75428f5b033056f8", "lessThan": "b287521e9e94bb342ebe5fd8c3fd7db9aef4e6f1", "status": "affected", "versionType": "git" }, { "version": "16b374ca439fb406e46e071f75428f5b033056f8", "lessThan": "f299522eda1566cbfbae4b15c82970fc41b03714", "status": "affected", "versionType": "git" }, { "version": "16b374ca439fb406e46e071f75428f5b033056f8", "lessThan": "945ebef997227ca8c20bad7f8a8358c8ee57a84a", "status": "affected", "versionType": "git" }, { "version": "16b374ca439fb406e46e071f75428f5b033056f8", "lessThan": "e411df81cd862ef3d5b878120b2a2fef0ca9cdb1", "status": "affected", "versionType": "git" }, { "version": "16b374ca439fb406e46e071f75428f5b033056f8", "lessThan": "9b367fe770b1b80d7bf64ed0d177544a44405f6e", "status": "affected", "versionType": "git" }, { "version": "16b374ca439fb406e46e071f75428f5b033056f8", "lessThan": "d34fb628f6ef522f996205a9e578216bbee09e84", "status": "affected", "versionType": "git" }, { "version": "16b374ca439fb406e46e071f75428f5b033056f8", "lessThan": "769b01ea68b6c49dc3cde6adf7e53927dacbd3a8", "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/nfs/filelayout/filelayout.c" ], "versions": [ { "version": "2.6.37", "status": "affected" }, { "version": "0", "lessThan": "2.6.37", "status": "unaffected", "versionType": "semver" }, { "version": "4.4.271", "lessThanOrEqual": "4.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.9.271", "lessThanOrEqual": "4.9.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.14.235", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.193", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.124", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.42", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.12.9", "lessThanOrEqual": "5.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.13", "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": "2.6.37", "versionEndExcluding": 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