CVE ID:	CVE-2023-51764
Description:	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 . but some other popular e-mail servers do not. To prevent attack variants (by always disallowing without ), 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.
Test IDs:	1.3.6.1.4.1.25623.1.1.10.2024.0029   1.3.6.1.4.1.25623.1.1.12.2024.6591.1   1.3.6.1.4.1.25623.1.0.833202   1.3.6.1.4.1.25623.1.0.885572   1.3.6.1.4.1.25623.1.1.4.2024.1149.1   1.3.6.1.4.1.25623.1.1.12.2024.6591.2   1.3.6.1.4.1.25623.1.0.885576   1.3.6.1.4.1.25623.1.1.4.2024.0012.1   1.3.6.1.4.1.25623.1.1.1.2.2024.3725   1.3.6.1.4.1.25623.1.0.114255   1.3.6.1.4.1.25623.1.0.833184
Cross References:	Common Vulnerability Exposure (CVE) ID: CVE-2023-51764 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JQ5WXFCW2N6G2PH3JXDTYW5PH5EBQEGO/ https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QRLF5SOS7TP5N7FQSEK2NFNB44ISVTZC/ https://access.redhat.com/security/cve/CVE-2023-51764 https://bugzilla.redhat.com/show_bug.cgi?id=2255563 https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html https://github.com/duy-31/CVE-2023-51764 https://github.com/eeenvik1/CVE-2023-51764 https://lwn.net/Articles/956533/ https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/ https://www.openwall.com/lists/oss-security/2024/01/22/1 https://www.postfix.org/announcements/postfix-3.8.5.html https://www.postfix.org/smtp-smuggling.html https://www.youtube.com/watch?v=V8KPV96g1To https://lists.debian.org/debian-lts-announce/2024/01/msg00020.html http://www.openwall.com/lists/oss-security/2023/12/24/1 http://www.openwall.com/lists/oss-security/2023/12/25/1 http://www.openwall.com/lists/oss-security/2024/05/09/3