{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-52440", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-02-20T12:30:33.291Z", "datePublished": "2024-02-21T07:21:00.438Z", "dateUpdated": "2026-08-15T12:23:46.483Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-15T12:23:46.483Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix slub overflow in ksmbd_decode_ntlmssp_auth_blob()\n\nIf authblob->SessionKey.Length is bigger than session key\nsize(CIFS_KEY_SIZE), slub overflow can happen in key exchange codes.\ncifs_arc4_crypt copy to session key array from SessionKey from client." } ], "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 in ksmbd's NTLMSSP SESSION_SETUP handling (fs/smb/server/), reached over TCP/445 via the in-kernel SMB server from a remote peer with no local access required.\nAC:L - An attacker who sets NTLMSSP_NEGOTIATE_KEY_XCH and supplies SessionKey.Length > CIFS_KEY_SIZE (40) reliably triggers cifs_arc4_crypt()'s unbounded write into sess->sess_key; no race or attacker-uncontrollable condition is required.\nPR:N - The overflow runs in the KEY_XCH path after ksmbd_auth_ntlmv2() regardless of whether authentication succeeds, so valid credentials are not required—only a configured username during the pre-auth handshake, which ZDI also assessed as unauthenticated.\nUI:N - Exploitation requires only attacker-sent SMB SESSION_SETUP messages; no victim user action is needed.\nS:U - This is standard in-kernel heap corruption leading to privilege escalation within the host kernel's security authority, not a VM/IOMMU/sandbox boundary cross.\nC:H - The heap OOB write corrupts ksmbd_session fields and adjacent SLUB objects, which can be leveraged for arbitrary kernel memory disclosure under standard heap-exploitation techniques.\nI:H - Attacker-controlled-length write past the 40-byte sess_key into session pointers/keys and adjacent slab objects is an out-of-bounds write enabling control-flow hijacking and RCE, as assessed by ZDI (ZDI-24-229).\nA:H - The SLUB overflow corrupts kernel heap metadata and session structures, causing reliable kernel oops/panic and denial of service of the host." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/auth.c" ], "versions": [ { "version": "c5049d2d73b2dc8e6bb64be633250bad1ae3d9ef", "lessThan": "bd554ed4fdc3d38404a1c43d428432577573e809", "status": "affected", "versionType": "git" }, { "version": "f9929ef6a2a55f03aac61248c6a3a987b8546f2a", "lessThan": "30fd6521b2fbd9b767e438e31945e5ea3e3a2fba", "status": "affected", "versionType": "git" }, { "version": "f9929ef6a2a55f03aac61248c6a3a987b8546f2a", "lessThan": "7f1d6cb0eb6af3a8088dc24b7ddee9a9711538c4", "status": "affected", "versionType": "git" }, { "version": "f9929ef6a2a55f03aac61248c6a3a987b8546f2a", "lessThan": "ecd7e1c562cb08e41957fcd4b0e404de5ab38e20", "status": "affected", "versionType": "git" }, { "version": "f9929ef6a2a55f03aac61248c6a3a987b8546f2a", "lessThan": "4b081ce0d830b684fdf967abc3696d1261387254", "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/smb/server/auth.c" ], "versions": [ { "version": "5.17", "status": "affected" }, { "version": "0", "lessThan": "5.17", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.52", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.4.15", "lessThanOrEqual": "6.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.5.2", "lessThanOrEqual": "6.5.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6", "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": "5.17", "versionEndExcluding": "6.1.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "6.4.15" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "6.5.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "6.6" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/bd554ed4fdc3d38404a1c43d428432577573e809" }, { "url": "https://git.kernel.org/stable/c/30fd6521b2fbd9b767e438e31945e5ea3e3a2fba" }, { "url": "https://git.kernel.org/stable/c/7f1d6cb0eb6af3a8088dc24b7ddee9a9711538c4" }, { "url": "https://git.kernel.org/stable/c/ecd7e1c562cb08e41957fcd4b0e404de5ab38e20" }, { "url": "https://git.kernel.org/stable/c/4b081ce0d830b684fdf967abc3696d1261387254" } ], "title": "ksmbd: fix slub overflow in ksmbd_decode_ntlmssp_auth_blob()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-02T22:55:41.777Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/bd554ed4fdc3d38404a1c43d428432577573e809", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/30fd6521b2fbd9b767e438e31945e5ea3e3a2fba", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/7f1d6cb0eb6af3a8088dc24b7ddee9a9711538c4", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/ecd7e1c562cb08e41957fcd4b0e404de5ab38e20", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/4b081ce0d830b684fdf967abc3696d1261387254", "tags": [ "x_transferred" ] } ] }, { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2023-52440", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-09-10T16:02:52.628151Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-09-11T17:33:31.499Z" } } ] } }