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CVE-2023-51764 Detail

Current 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.


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  5.3 MEDIUM
Vector:  CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have published a CVSS score for this CVE based on publicly available information at the time of analysis. The CNA has not provided a score within the CVE List.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
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 
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
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JQ5WXFCW2N6G2PH3JXDTYW5PH5EBQEGO/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QRLF5SOS7TP5N7FQSEK2NFNB44ISVTZC/
https://lwn.net/Articles/956533/
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
https://www.postfix.org/announcements/postfix-3.8.5.html
https://www.postfix.org/smtp-smuggling.html Exploit  Mitigation  Vendor Advisory 
https://www.youtube.com/watch?v=V8KPV96g1To Exploit 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-345 Insufficient Verification of Data Authenticity cwe source acceptance level NIST  

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Change History

12 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2023-51764
NVD Published Date:
12/24/2023
NVD Last Modified:
01/30/2024
Source:
MITRE