# CVE-2023-3347: Samba: smb2 packet signing is not enforced when "server signing = required" is set Status: published. Published: 2023-07-20. Updated: 2026-11-07. A vulnerability was found in Samba's SMB2 packet signing mechanism. The SMB2 packet signing is not enforced if an admin configured "server signing = required" or for SMB2 connections to Domain Controllers where SMB2 packet signing is mandatory. This flaw allows an attacker to perform attacks, such as a man-in-the-middle attack, by intercepting the network traffic and modifying the SMB2 messages between client and server, affecting the integrity of the data. ## Remediation No remediation reported in collected sources ## Affected products and versions - Red Hat / Red Hat Enterprise Linux 8 (samba): ≥ 0:4.17.5-3.el8_8; < * (unaffected, rpm). Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 9 (samba): ≥ 0:4.17.5-103.el9_2; < * (unaffected, rpm). Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 6 (samba): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 6 (samba4): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 7 (samba): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat Storage 3 (samba): Version range not reported. Source: CNA: redhat ## NVD configuration conditions Affected CPE matches depend on the following AND/OR and negation conditions: ```json [ { "negate": false, "nodes": [ { "cpeMatch": [ { "criteria": "cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*", "versionEndExcluding": "4.17.10", "versionStartIncluding": "4.17.0", "vulnerable": true }, { "criteria": "cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*", "versionEndExcluding": "4.18.5", "versionStartIncluding": "4.18.0", "vulnerable": true } ], "negate": false, "operator": "OR" } ], "operator": "OR" }, { "negate": false, "nodes": [ { "cpeMatch": [ { "criteria": "cpe:2.3:a:redhat:storage:3.0:*:*:*:*:*:*:*", "vulnerable": true }, { "criteria": "cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*", "vulnerable": true }, { "criteria": "cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*", "vulnerable": true } ], "negate": false, "operator": "OR" } ], "operator": "OR" }, { "negate": false, "nodes": [ { "cpeMatch": [ { "criteria": "cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*", "vulnerable": true } ], "negate": false, "operator": "OR" } ], "operator": "OR" } ] ``` ## Severity and prioritization - CVSS 3.1: 5.9 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N; source: CNA: redhat - CVSS 3.1: 5.9 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N; source: NVD: nvd@nist.gov - CVSS 3.1: 5.9 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N; source: NVD: secalert@redhat.com - CISA KEV: No listing in collected sources - EPSS: 0.44% as of 2026-11-06; percentile 38.05% - SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP - Weaknesses: CWE-347, CWE-924 ## Exploit evidence No exploit evidence in collected sources. This is not proof of no exploitation. ## References - https://access.redhat.com/errata/RHSA-2023:4325 (CNA: redhat; vendor-advisory, x_refsource_REDHAT) - https://access.redhat.com/errata/RHSA-2023:4328 (CNA: redhat; vendor-advisory, x_refsource_REDHAT) - https://access.redhat.com/security/cve/CVE-2023-3347 (CNA: redhat; vdb-entry, x_refsource_REDHAT) - https://bugzilla.redhat.com/show_bug.cgi?id=2222792 (CNA: redhat; issue-tracking, x_refsource_REDHAT) - https://www.samba.org/samba/security/CVE-2023-3347.html (CNA: redhat) - https://access.redhat.com/errata/RHSA-2023:4325 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred) - https://access.redhat.com/errata/RHSA-2023:4328 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred) - https://access.redhat.com/security/cve/CVE-2023-3347 (ADP: CVE; vdb-entry, x_refsource_REDHAT, x_transferred) - https://bugzilla.redhat.com/show_bug.cgi?id=2222792 (ADP: CVE; issue-tracking, x_refsource_REDHAT, x_transferred) - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BPCSGND7LO467AJGR5DYBGZLTCGTOBCC/ (ADP: CVE; x_transferred) - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OT74M42E6C36W7PQVY3OS4ZM7DVYB64Z/ (ADP: CVE; x_transferred) - https://security.netapp.com/advisory/ntap-20230731-0010/ (ADP: CVE; x_transferred) - https://www.debian.org/security/2023/dsa-5477 (ADP: CVE; x_transferred) - https://www.samba.org/samba/security/CVE-2023-3347.html (ADP: CVE; x_transferred) - https://access.redhat.com/errata/RHSA-2023:4325 (secalert@redhat.com; Third Party Advisory) - https://access.redhat.com/errata/RHSA-2023:4328 (secalert@redhat.com; Third Party Advisory) - https://access.redhat.com/security/cve/CVE-2023-3347 (secalert@redhat.com; Third Party Advisory) - https://bugzilla.redhat.com/show_bug.cgi?id=2222792 (secalert@redhat.com; Issue Tracking, Third Party Advisory) - https://www.samba.org/samba/security/CVE-2023-3347.html (secalert@redhat.com; Vendor Advisory) - https://access.redhat.com/errata/RHSA-2023:4325 (af854a3a-2127-422b-91ae-364da2661108; Third Party Advisory) - https://access.redhat.com/errata/RHSA-2023:4328 (af854a3a-2127-422b-91ae-364da2661108; Third Party Advisory) - https://access.redhat.com/security/cve/CVE-2023-3347 (af854a3a-2127-422b-91ae-364da2661108; Third Party Advisory) - https://bugzilla.redhat.com/show_bug.cgi?id=2222792 (af854a3a-2127-422b-91ae-364da2661108; Issue Tracking, Third Party Advisory) - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BPCSGND7LO467AJGR5DYBGZLTCGTOBCC/ (af854a3a-2127-422b-91ae-364da2661108) - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OT74M42E6C36W7PQVY3OS4ZM7DVYB64Z/ (af854a3a-2127-422b-91ae-364da2661108) - https://security.netapp.com/advisory/ntap-20230731-0010/ (af854a3a-2127-422b-91ae-364da2661108) - https://www.debian.org/security/2023/dsa-5477 (af854a3a-2127-422b-91ae-364da2661108) - https://www.samba.org/samba/security/CVE-2023-3347.html (af854a3a-2127-422b-91ae-364da2661108; Vendor Advisory) ## Provenance - CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2023-3347; retrieved 2026-11-07; source updated 2026-11-07 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-3347; retrieved 2026-11-07; source updated 2026-11-07 - FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2023-3347; retrieved 2026-11-07; source updated Not reported Revision: 58a69db227c6046a60c651a063d165d6976681b0731a0506615c9cbb57f99795 Canonical: https://y2.dev/cve/CVE-2023-3347 ## Agent and API access Public CVE pages, Markdown, and JSON are free to read without an account or API key. - Public catalog: https://y2.dev/cve/index.json. 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