{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-47259", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-21T13:27:52.125Z", "datePublished": "2024-05-21T14:19:52.738Z", "dateUpdated": "2026-08-05T08:47:00.677Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:47:00.677Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: Fix use-after-free in nfs4_init_client()\n\nKASAN reports a use-after-free when attempting to mount two different\nexports through two different NICs that belong to the same server.\n\nOlga was able to hit this with kernels starting somewhere between 5.7\nand 5.10, but I traced the patch that introduced the clear_bit() call to\n4.13. So something must have changed in the refcounting of the clp\npointer to make this call to nfs_put_client() the very last one." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - This is NFS client code in fs/nfs/nfs4client.c (nfs4_init_client), reached via local mount or NFSv4 referral/submount automount (nfs_d_automount → nfs4_create_referral_server → nfs4_set_client → nfs_get_client), not via nfsd/ksmbd or unsolicited packet processing.\nAC:L - An attacker who can mount two exports via different NICs of the same server, or drive referral/migration to a trunking-matched address (including a cooperating/malicious NFS server), fully controls the trunking-discovery path that yields clp != old and frees clp before clear_bit; no race or layout outside attacker influence is required.\nPR:L - Although a fresh NFS mount needs CAP_SYS_ADMIN (nfs_fs_type lacks FS_USERNS_MOUNT), an unprivileged user can reach nfs4_init_client via NFSv4 referral/submount automounts or migration on an already-mounted export, matching prior CNA scoring of this same init path.\nUI:N - Once an NFS share is present, the attacker triggers the bug themselves by mounting/walking a referral or exercising migration; no separate victim action is required beyond that environmental mount.\nS:U - The use-after-free corrupts host kernel heap state within the same OS security authority and does not cross a VM, IOMMU, or other security-authority boundary.\nC:H - nfs_put_client can kfree the nfs_client while clear_bit still writes clp->cl_flags, a classic slab UAF; reclaim of the freed object enables arbitrary kernel memory disclosure under standard UAF exploitation.\nI:H - The post-free clear_bit is a write into freed nfs_client memory, and heap spraying the reclaimed object yields arbitrary-write and control-flow hijacking primitives consistent with scoring other kernel UAFs as High integrity.\nA:H - Use-after-free of struct nfs_client causes kernel oops/panic when the freed object is touched (KASAN reported this path), so availability impact is High even without a full exploit." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfs/nfs4client.c" ], "versions": [ { "version": "8dcbec6d20eb881ba368d0aebc3a8a678aebb1da", "lessThan": "c7eab9e2d7b4e983ce280276fb920af649955897", "status": "affected", "versionType": "git" }, { "version": "8dcbec6d20eb881ba368d0aebc3a8a678aebb1da", "lessThan": "42c10b0db064e45f5c5ae7019bbf2168ffab766c", "status": "affected", "versionType": "git" }, { "version": "8dcbec6d20eb881ba368d0aebc3a8a678aebb1da", "lessThan": "3e3c7ebbfac152d08be75c92802a64a1f6471a15", "status": "affected", "versionType": "git" }, { "version": "8dcbec6d20eb881ba368d0aebc3a8a678aebb1da", "lessThan": "c3b6cf64dfe4ef96e7341508d50d6998da7062c7", "status": "affected", "versionType": "git" }, { "version": "8dcbec6d20eb881ba368d0aebc3a8a678aebb1da", "lessThan": "72651c6579a25317a90536181d311c663d0329ab", "status": "affected", "versionType": "git" }, { "version": "8dcbec6d20eb881ba368d0aebc3a8a678aebb1da", "lessThan": "476bdb04c501fc64bf3b8464ffddefc8dbe01577", "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/nfs4client.c" ], "versions": [ { "version": "4.13", "status": "affected" }, { "version": "0", "lessThan": "4.13", "status": "unaffected", "versionType": "semver" }, { "version": "4.14.237", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.195", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.126", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.44", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.12.11", "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": "4.13", "versionEndExcluding": "4.14.237" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.13", "versionEndExcluding": "4.19.195" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.13", "versionEndExcluding": "5.4.126" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.13", "versionEndExcluding": "5.10.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.13", "versionEndExcluding": "5.12.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.13", "versionEndExcluding": "5.13" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/c7eab9e2d7b4e983ce280276fb920af649955897" }, { "url": "https://git.kernel.org/stable/c/42c10b0db064e45f5c5ae7019bbf2168ffab766c" }, { "url": "https://git.kernel.org/stable/c/3e3c7ebbfac152d08be75c92802a64a1f6471a15" }, { "url": "https://git.kernel.org/stable/c/c3b6cf64dfe4ef96e7341508d50d6998da7062c7" }, { "url": "https://git.kernel.org/stable/c/72651c6579a25317a90536181d311c663d0329ab" }, { "url": "https://git.kernel.org/stable/c/476bdb04c501fc64bf3b8464ffddefc8dbe01577" } ], "title": "NFS: Fix use-after-free in nfs4_init_client()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CISA ADP Vulnrichment", "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2021-47259", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2024-05-22T16:41:04.603993Z" } } } ], "affected": [ { "cpes": [ "cpe:2.3:o:linux:linux_kernel:4.13:*:*:*:*:*:*:*" ], "vendor": "linux", "product": "linux_kernel", "versions": [ { "status": "affected", "version": "4.13" } ], "defaultStatus": "unknown" }, { "cpes": [ "cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*" ], "vendor": "linux", "product": "linux_kernel", "versions": [ { "status": "affected", "version": "8dcbec6d20eb", "lessThan": "476bdb04c501", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free" } ] } ], "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-04T17:14:09.514Z" } }, { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:32:07.994Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/c7eab9e2d7b4e983ce280276fb920af649955897", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/42c10b0db064e45f5c5ae7019bbf2168ffab766c", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/3e3c7ebbfac152d08be75c92802a64a1f6471a15", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/c3b6cf64dfe4ef96e7341508d50d6998da7062c7", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/72651c6579a25317a90536181d311c663d0329ab", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/476bdb04c501fc64bf3b8464ffddefc8dbe01577", "tags": [ "x_transferred" ] } ] } ] } }