{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-50286", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-10-21T19:36:19.984Z", "datePublished": "2024-11-19T01:30:29.948Z", "dateUpdated": "2026-08-05T11:43:05.795Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:43:05.795Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix slab-use-after-free in ksmbd_smb2_session_create\n\nThere is a race condition between ksmbd_smb2_session_create and\nksmbd_expire_session. This patch add missing sessions_table_lock\nwhile adding/deleting session from global session table." } ], "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 - ksmbd is the in-kernel SMB server; the entire path is driven by SMB2 SESSION_SETUP packets arriving on TCP/445 from a remote peer. No local access is needed.\nAC:L - The attacker controls both sides of the race — one connection deterministically triggers ksmbd_expire_session()'s unlocked hash_del()+kfree() via a second SessionId=0 SESSION_SETUP, while parallel connections drive hash_add()/__session_lookup() on the same 8-bucket global table, making bucket collisions near-certain.\nPR:N - smb2_check_user_session() explicitly exempts SMB2_SESSION_SETUP_HE from the conn-good/session-validity check, and ksmbd_smb2_session_create() plus ksmbd_session_register() run before any NTLMSSP/Kerberos credential is processed. An unauthenticated remote attacker reaches the bug.\nUI:N - Exploitation requires only that the attacker open TCP connections to the listening ksmbd port and send SESSION_SETUP requests; no action by any local user or administrator is involved.\nS:U - The corruption is confined to kernel slab memory within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The UAF lets __session_lookup()/ksmbd_session_lookup_slowpath() return a dangling struct ksmbd_session that is then used as work->sess, exposing sess->user credentials, sess_key, smb3signingkey and smb3encryptionkey/decryptionkey read out of attacker-groomable freed memory.\nI:H - hlist_add_head() writes a kernel pointer (first->pprev = &n->next) into the freed, sprayable slab object, and __session_lookup() writes sess->last_active into freed memory — a write primitive usable for heap grooming and control-flow hijack.\nA:H - Corrupting the global session hlist and using a freed session reliably produces a slab-use-after-free oops or panic, remotely and repeatably without authentication." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/mgmt/user_session.c" ], "versions": [ { "version": "0626e6641f6b467447c81dd7678a69c66f7746cf", "lessThan": "f56446ba5378d19e31040b548a14ee9a8f1500ea", "status": "affected", "versionType": "git" }, { "version": "0626e6641f6b467447c81dd7678a69c66f7746cf", "lessThan": "e923503a56b3385b64ae492e3225e4623f560c5b", "status": "affected", "versionType": "git" }, { "version": "0626e6641f6b467447c81dd7678a69c66f7746cf", "lessThan": "e7a2ad2044377853cf8c59528dac808a08a99c72", "status": "affected", "versionType": "git" }, { "version": "0626e6641f6b467447c81dd7678a69c66f7746cf", "lessThan": "0a77715db22611df50b178374c51e2ba0d58866e", "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/mgmt/user_session.c" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.117", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.61", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.11.8", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12", "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", "versionEndExcluding": "6.1.117" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.6.61" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.11.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f56446ba5378d19e31040b548a14ee9a8f1500ea" }, { "url": "https://git.kernel.org/stable/c/e923503a56b3385b64ae492e3225e4623f560c5b" }, { "url": "https://git.kernel.org/stable/c/e7a2ad2044377853cf8c59528dac808a08a99c72" }, { "url": "https://git.kernel.org/stable/c/0a77715db22611df50b178374c51e2ba0d58866e" } ], "title": "ksmbd: fix slab-use-after-free in ksmbd_smb2_session_create", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2024-50286", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2025-03-06T16:07:56.848996Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-03-06T16:14:33.108Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T22:28:07.988Z" } } ] } }