CVEvulnerability
CVE-2023-51764
5.3 MEDIUM
Official page ↗
- Status
- Modified
- Published
- 2023-12-24
- Last modified
- 2026-10-08
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 5.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- Weaknesses
- CWE-345
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 <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 configurations
• postfix postfix (< 3.5.23)
• postfix postfix (>= 3.6.0 < 3.6.13)
• postfix postfix (>= 3.7.0 < 3.7.9)
• postfix postfix (>= 3.8.0 < 3.8.4)
• fedoraproject fedora 38
• fedoraproject fedora 39
• redhat enterprise linux 8.0
• redhat enterprise linux 9.0
Related
Weakness · CWE (1)
- CWE-345 Insufficient Verification of Data Authenticity weakness
References
- http://www.openwall.com/lists/oss-security/2023/12/24/1 Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2023/12/25/1 Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2024/05/09/3 www.openwall.com
- https://access.redhat.com/security/cve/CVE-2023-51764 Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2255563 Issue Tracking, Third Party Advisory
- https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html Technical Description
- https://github.com/duy-31/CVE-2023-51764 Exploit, Third Party Advisory
- https://github.com/eeenvik1/CVE-2023-51764 Exploit, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2024/01/msg00020.html lists.debian.org
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JQ5WXFCW2N6G2PH3JXDTYW5PH5EBQEGO/ lists.fedoraproject.org
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QRLF5SOS7TP5N7FQSEK2NFNB44ISVTZC/ lists.fedoraproject.org
- https://lwn.net/Articles/956533/ lwn.net
- https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/ Technical Description, Third Party Advisory
- https://www.openwall.com/lists/oss-security/2024/01/22/1 www.openwall.com
- https://www.postfix.org/announcements/postfix-3.8.5.html www.postfix.org
- https://www.postfix.org/smtp-smuggling.html Exploit, Mitigation, Vendor Advisory
- https://www.youtube.com/watch?v=V8KPV96g1To Exploit
- http://www.openwall.com/lists/oss-security/2023/12/24/1 Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2023/12/25/1 Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2024/05/09/3 www.openwall.com
- https://access.redhat.com/security/cve/CVE-2023-51764 Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2255563 Issue Tracking, Third Party Advisory
- https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html Technical Description
- https://github.com/duy-31/CVE-2023-51764 Exploit, Third Party Advisory
- https://github.com/eeenvik1/CVE-2023-51764 Exploit, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2024/01/msg00020.html lists.debian.org
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JQ5WXFCW2N6G2PH3JXDTYW5PH5EBQEGO/ lists.fedoraproject.org
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QRLF5SOS7TP5N7FQSEK2NFNB44ISVTZC/ lists.fedoraproject.org
- https://lists.fedoraproject.org/archives/list/[email protected]/message/JQ5WXFCW2N6G2PH3JXDTYW5PH5EBQEGO/ lists.fedoraproject.org
- https://lists.fedoraproject.org/archives/list/[email protected]/message/QRLF5SOS7TP5N7FQSEK2NFNB44ISVTZC/ lists.fedoraproject.org
- https://lwn.net/Articles/956533/ lwn.net
- https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/ Technical Description, Third Party Advisory
- https://www.openwall.com/lists/oss-security/2024/01/22/1 www.openwall.com
- https://www.postfix.org/announcements/postfix-3.8.5.html www.postfix.org
- https://www.postfix.org/smtp-smuggling.html Exploit, Mitigation, Vendor Advisory
- https://www.youtube.com/watch?v=V8KPV96g1To Exploit