{"id":"CVE-2023-32249","state":"PUBLISHED","title":"ksmbd: not allow guest user on multichannel","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: not allow guest user on multichannel\n\nThis patch return STATUS_NOT_SUPPORTED if binding session is guest.","publishedAt":"2025-08-16T13:25:49.645Z","updatedAt":"2026-08-15T12:23:40.636Z","severity":{"score":9.1,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f5a544e3bab78142207e0242d22442db85ba1eff","status":"affected","lessThan":"ed76d3a8910be06cd4e4ba63bf6075bf903945a1","versionType":"git"},{"version":"f5a544e3bab78142207e0242d22442db85ba1eff","status":"affected","lessThan":"1f0490586544455e5be698be2e6c30077b4ec461","versionType":"git"},{"version":"f5a544e3bab78142207e0242d22442db85ba1eff","status":"affected","lessThan":"4a98e859c4673013385a54084e0cd865695ca072","versionType":"git"},{"version":"f5a544e3bab78142207e0242d22442db85ba1eff","status":"affected","lessThan":"088131b7b01099720a528a72005ff17868705d40","versionType":"git"},{"version":"f5a544e3bab78142207e0242d22442db85ba1eff","status":"affected","lessThan":"3353ab2df5f68dab7da8d5ebb427a2d265a1f2b2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ksmbd/smb2pdu.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"5.15.112","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.28","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2.15","status":"unaffected","lessThanOrEqual":"6.2.*","versionType":"semver"},{"version":"6.3.2","status":"unaffected","lessThanOrEqual":"6.3.*","versionType":"semver"},{"version":"6.4","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ksmbd/smb2pdu.c"]}],"references":["https://git.kernel.org/stable/c/ed76d3a8910be06cd4e4ba63bf6075bf903945a1","https://git.kernel.org/stable/c/1f0490586544455e5be698be2e6c30077b4ec461","https://git.kernel.org/stable/c/4a98e859c4673013385a54084e0cd865695ca072","https://git.kernel.org/stable/c/088131b7b01099720a528a72005ff17868705d40","https://git.kernel.org/stable/c/3353ab2df5f68dab7da8d5ebb427a2d265a1f2b2"],"weaknesses":[],"ingestedAt":"2026-10-29T20:06:00.499Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/32xxx/CVE-2023-32249.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-32249","state":"PUBLISHED","datePublished":"2025-08-16T13:25:49.645Z","dateUpdated":"2026-08-15T12:23:40.636Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2023-05-05T10:00:07.895Z"},"containers":{"cna":{"title":"ksmbd: not allow guest user on multichannel","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: not allow guest user on multichannel\n\nThis patch return STATUS_NOT_SUPPORTED if binding session is guest."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f5a544e3bab78142207e0242d22442db85ba1eff","status":"affected","lessThan":"ed76d3a8910be06cd4e4ba63bf6075bf903945a1","versionType":"git"},{"version":"f5a544e3bab78142207e0242d22442db85ba1eff","status":"affected","lessThan":"1f0490586544455e5be698be2e6c30077b4ec461","versionType":"git"},{"version":"f5a544e3bab78142207e0242d22442db85ba1eff","status":"affected","lessThan":"4a98e859c4673013385a54084e0cd865695ca072","versionType":"git"},{"version":"f5a544e3bab78142207e0242d22442db85ba1eff","status":"affected","lessThan":"088131b7b01099720a528a72005ff17868705d40","versionType":"git"},{"version":"f5a544e3bab78142207e0242d22442db85ba1eff","status":"affected","lessThan":"3353ab2df5f68dab7da8d5ebb427a2d265a1f2b2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ksmbd/smb2pdu.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"5.15.112","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.28","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2.15","status":"unaffected","lessThanOrEqual":"6.2.*","versionType":"semver"},{"version":"6.3.2","status":"unaffected","lessThanOrEqual":"6.3.*","versionType":"semver"},{"version":"6.4","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ksmbd/smb2pdu.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/ed76d3a8910be06cd4e4ba63bf6075bf903945a1"},{"url":"https://git.kernel.org/stable/c/1f0490586544455e5be698be2e6c30077b4ec461"},{"url":"https://git.kernel.org/stable/c/4a98e859c4673013385a54084e0cd865695ca072"},{"url":"https://git.kernel.org/stable/c/088131b7b01099720a528a72005ff17868705d40"},{"url":"https://git.kernel.org/stable/c/3353ab2df5f68dab7da8d5ebb427a2d265a1f2b2"}],"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:N","baseScore":9.1,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The flaw is in ksmbd (fs/ksmbd/) SMB2 SESSION_SETUP multichannel binding, reached over TCP/445 from a remote peer with no local access required.\nAC:L - The attacker fully controls the binding connection and SESSION_SETUP messages; SessionIds are sequential ida allocations and the bind path needs no race or special memory layout, so the hijack is reliably triggerable once a live session exists.\nPR:N - ZDI-23-697 and the vulnerable ntlm_authenticate path show anonymous/guest reauthentication skips credential verification during binding, so no valid SMB credentials for the target session are required.\nUI:N - Exploitation requires only attacker-sent SMB negotiate/session-setup traffic against an already-active victim session; no additional victim action is needed.\nS:U - Impact stays within the ksmbd server’s authority (hijacked SMB session and its share/file access) and does not cross a VM, kernel/user, or other security boundary.\nC:H - Successful binding attaches the attacker to an arbitrary live session via global session lookup, granting full read access to that user’s connected shares and open files.\nI:H - The hijacked session retains the victim’s authorization for tree connects and file operations, so the attacker can create, modify, or delete data with the victim’s SMB privileges.\nA:N - This is an authentication/session-isolation bug, not memory corruption; it does not cause kernel oops/panic or otherwise deny availability of the component."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-15T12:23:40.636Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"5.15.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.1.28"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.2.15"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.3.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.4"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}