{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-4515", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2023-08-24T10:34:48.702Z", "datePublished": "2025-08-16T13:25:50.562Z", "dateUpdated": "2026-08-05T09:09:51.240Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:09:51.240Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: validate command request size\n\nIn commit 2b9b8f3b68ed (\"ksmbd: validate command payload size\"), except\nfor SMB2_OPLOCK_BREAK_HE command, the request size of other commands\nis not checked, it's not expected. Fix it by add check for request\nsize of other commands." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H", "baseScore": 9.1, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable code is in ksmbd (fs/smb/server/), the in-kernel SMB server reached over TCP/445; a remote peer triggers it by sending a crafted SMB2 PDU that fails StructureSize2 validation.\nAC:L - An attacker fully controls StructureSize2 and the RFC1002 PDU length and can reliably send a short pre-auth SESSION_SETUP (e.g. StructureSize2=1 with pdu_size=68) that passes the incomplete check and OOBs in smb2_get_data_area_len; no race or external condition is required.\nPR:N - ksmbd_smb2_check_message runs for SMB2_NEGOTIATE, SMB2_SESSION_SETUP, and SMB2_ECHO, which smb2_check_user_session explicitly allows without a session, so the OOB is reachable before any credential verification.\nUI:N - Exploitation requires only attacker-sent SMB2 packets to a listening ksmbd instance; no victim user action is needed.\nS:U - Impact stays within the host kernel/ksmbd security authority (heap OOB read/DoS); this is not a VM escape, IOMMU bypass, or other cross-authority boundary change.\nC:H - Missing StructureSize2 matching allows slab out-of-bounds reads of fixed command fields (and subsequent use of those values as security-blob offset/length), which can disclose adjacent kernel heap contents under standard grooming; per guidance OOB reads score C:H.\nI:N - The defect is an out-of-bounds read from incomplete request-size validation; unlike related ksmbd heap overflows there is no demonstrated out-of-bounds write or direct integrity/control-flow primitive from this bug alone.\nA:H - The slab OOB read can fault under KFENCE/DEBUG_PAGEALLOC or panic under KASAN (as in the related KASAN report for the incomplete parent fix), and the attacker can retrigger it pre-authentication at will." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/smb2misc.c" ], "versions": [ { "version": "35f450f54dca1519bb24faacd0428db09f89a11f", "lessThan": "595679098bdcdbfbba91ebe07a2f7f208df93870", "status": "affected", "versionType": "git" }, { "version": "9650cf70ec9d94ff34daa088b643229231723c26", "lessThan": "c6bef3bc30fd4a175aef846b7d928a6c40d091cd", "status": "affected", "versionType": "git" }, { "version": "2b9b8f3b68edb3d67d79962f02e26dbb5ae3808d", "lessThan": "ff7236b66d69582f90cf5616e63cfc3dc18142bb", "status": "affected", "versionType": "git" }, { "version": "2b9b8f3b68edb3d67d79962f02e26dbb5ae3808d", "lessThan": "5aa4fda5aa9c2a5a7bac67b4a12b089ab81fee3c", "status": "affected", "versionType": "git" }, { "version": "768caf4019f0391c0b6452afe34cea1704133f7b", "status": "affected", "versionType": "git" }, { "version": "5.15.121", "lessThan": "5.15.127", "status": "affected", "versionType": "semver" }, { "version": "6.1.36", "lessThan": "6.1.46", "status": "affected", "versionType": "semver" }, { "version": "6.3.10", "lessThan": "6.4", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/smb2misc.c" ], "versions": [ { "version": "6.4", "status": "affected" }, { "version": "0", "lessThan": "6.4", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.127", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.46", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.4.11", "lessThanOrEqual": "6.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.5", "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": "5.15.121", "versionEndExcluding": "5.15.127" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.36", "versionEndExcluding": "6.1.46" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.4.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3.10" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/595679098bdcdbfbba91ebe07a2f7f208df93870" }, { "url": "https://git.kernel.org/stable/c/c6bef3bc30fd4a175aef846b7d928a6c40d091cd" }, { "url": "https://git.kernel.org/stable/c/ff7236b66d69582f90cf5616e63cfc3dc18142bb" }, { "url": "https://git.kernel.org/stable/c/5aa4fda5aa9c2a5a7bac67b4a12b089ab81fee3c" } ], "title": "ksmbd: validate command request size", "x_generator": { "engine": "bippy-1.2.0" } } } }