{"dataType":"CVE_RECORD","cveMetadata":{"state":"PUBLISHED","cveId":"CVE-2023-51764","assignerOrgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","assignerShortName":"mitre","dateUpdated":"2025-11-04T22:05:26.900Z","dateReserved":"2023-12-24T00:00:00.000Z","datePublished":"2023-12-24T00:00:00.000Z"},"containers":{"cna":{"providerMetadata":{"orgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","shortName":"mitre","dateUpdated":"2024-06-10T18:07:59.991Z"},"descriptions":[{"lang":"en","value":"Postfix through 3.8.5 allows SMTP smuggling unless configured with smtpd_data_restrictions=reject_unauth_pipelining and smtpd_discard_ehlo_keywords=chunking (or certain other options that exist in recent versions). Remote attackers can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address, allowing bypass of an SPF protection mechanism. This occurs because Postfix supports <LF>.<CR><LF> but some other popular e-mail servers do not. To prevent attack variants (by always disallowing <LF> without <CR>), a different solution is required, such as the smtpd_forbid_bare_newline=yes option with a Postfix minimum version of 3.5.23, 3.6.13, 3.7.9, 3.8.4, or 3.9."}],"affected":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}],"references":[{"url":"https://www.postfix.org/smtp-smuggling.html"},{"url":"https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/"},{"name":"[oss-security] 20231224 Re: Re: New SMTP smuggling attack","tags":["mailing-list"],"url":"http://www.openwall.com/lists/oss-security/2023/12/24/1"},{"name":"[oss-security] 20231225 Re: Re: New SMTP smuggling attack","tags":["mailing-list"],"url":"http://www.openwall.com/lists/oss-security/2023/12/25/1"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2255563"},{"url":"https://access.redhat.com/security/cve/CVE-2023-51764"},{"url":"https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html"},{"url":"https://github.com/eeenvik1/CVE-2023-51764"},{"url":"https://github.com/duy-31/CVE-2023-51764"},{"url":"https://www.youtube.com/watch?v=V8KPV96g1To"},{"name":"FEDORA-2024-c839e7294f","tags":["vendor-advisory"],"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QRLF5SOS7TP5N7FQSEK2NFNB44ISVTZC/"},{"name":"FEDORA-2024-5c186175f2","tags":["vendor-advisory"],"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JQ5WXFCW2N6G2PH3JXDTYW5PH5EBQEGO/"},{"url":"https://lwn.net/Articles/956533/"},{"url":"https://www.openwall.com/lists/oss-security/2024/01/22/1"},{"url":"https://www.postfix.org/announcements/postfix-3.8.5.html"},{"name":"[debian-lts-announce] 20240130 [SECURITY] [DLA 3725-1] postfix security update","tags":["mailing-list"],"url":"https://lists.debian.org/debian-lts-announce/2024/01/msg00020.html"},{"name":"[oss-security] 20240508 Re: New SMTP smuggling attack","tags":["mailing-list"],"url":"http://www.openwall.com/lists/oss-security/2024/05/09/3"}],"problemTypes":[{"descriptions":[{"type":"text","lang":"en","description":"n/a"}]}]},"adp":[{"title":"CVE Program Container","references":[{"url":"https://www.postfix.org/smtp-smuggling.html","tags":["x_transferred"]},{"url":"https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/","tags":["x_transferred"]},{"name":"[oss-security] 20231224 Re: Re: New SMTP smuggling attack","tags":["mailing-list","x_transferred"],"url":"http://www.openwall.com/lists/oss-security/2023/12/24/1"},{"name":"[oss-security] 20231225 Re: Re: New SMTP smuggling attack","tags":["mailing-list","x_transferred"],"url":"http://www.openwall.com/lists/oss-security/2023/12/25/1"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2255563","tags":["x_transferred"]},{"url":"https://access.redhat.com/security/cve/CVE-2023-51764","tags":["x_transferred"]},{"url":"https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html","tags":["x_transferred"]},{"url":"https://github.com/eeenvik1/CVE-2023-51764","tags":["x_transferred"]},{"url":"https://github.com/duy-31/CVE-2023-51764","tags":["x_transferred"]},{"url":"https://www.youtube.com/watch?v=V8KPV96g1To","tags":["x_transferred"]},{"name":"FEDORA-2024-c839e7294f","tags":["vendor-advisory","x_transferred"],"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QRLF5SOS7TP5N7FQSEK2NFNB44ISVTZC/"},{"name":"FEDORA-2024-5c186175f2","tags":["vendor-advisory","x_transferred"],"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JQ5WXFCW2N6G2PH3JXDTYW5PH5EBQEGO/"},{"url":"https://lwn.net/Articles/956533/","tags":["x_transferred"]},{"url":"https://www.openwall.com/lists/oss-security/2024/01/22/1","tags":["x_transferred"]},{"url":"https://www.postfix.org/announcements/postfix-3.8.5.html","tags":["x_transferred"]},{"name":"[debian-lts-announce] 20240130 [SECURITY] [DLA 3725-1] postfix security update","tags":["mailing-list","x_transferred"],"url":"https://lists.debian.org/debian-lts-announce/2024/01/msg00020.html"},{"name":"[oss-security] 20240508 Re: New SMTP smuggling attack","tags":["mailing-list","x_transferred"],"url":"http://www.openwall.com/lists/oss-security/2024/05/09/3"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QRLF5SOS7TP5N7FQSEK2NFNB44ISVTZC/"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JQ5WXFCW2N6G2PH3JXDTYW5PH5EBQEGO/"}],"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2025-11-04T22:05:26.900Z"}}]},"dataVersion":"5.2"}