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Mend.io Vulnerability Database

CVE-2023-51764

Good to know:

Date: December 24, 2023

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.

Language: C

Severity Score

5.3

Related Resources (19)

Url: https://lists.debian.org/debian-lts-announce/2024/01/msg00020.html

Url: https://www.youtube.com/watch?v=V8KPV96g1To

Url: https://bugzilla.redhat.com/show_bug.cgi?id=2255563

Url: https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html

Url: https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JQ5WXFCW2N6G2PH3JXDTYW5PH5EBQEGO/

Url: https://access.redhat.com/security/cve/CVE-2023-51764

Url: https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QRLF5SOS7TP5N7FQSEK2NFNB44ISVTZC/

Url: https://www.postfix.org/smtp-smuggling.html

Url: https://lwn.net/Articles/956533/

Url: https://www.openwall.com/lists/oss-security/2024/01/22/1

Url: https://github.com/eeenvik1/CVE-2023-51764

Url: https://github.com/duy-31/CVE-2023-51764

Url: https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/

Url: http://www.openwall.com/lists/oss-security/2023/12/25/1

Url: https://nvd.nist.gov/vuln/detail/CVE-2023-51764

Url: http://www.openwall.com/lists/oss-security/2023/12/24/1

Url: https://security-tracker.debian.org/tracker/CVE-2023-51764

Url: https://www.postfix.org/announcements/postfix-3.8.5.html

Url: https://www.mend.io/vulnerability-database/CVE-2023-51764

Severity Score

5.3

Weakness Type (CWE)

Insufficient Verification of Data Authenticity

CWE-345

Top Fix

Upgrade Version

Upgrade to version v3.5.23,v3.6.13,v3.7.9,v3.8.4,v3.9

Learn More

CVSS v3.1

Base Score:	5.3
Attack Vector (AV):	NETWORK
Attack Complexity (AC):	LOW
Privileges Required (PR):	NONE
User Interaction (UI):	NONE
Scope (S):	UNCHANGED
Confidentiality (C):	NONE
Integrity (I):	LOW
Availability (A):	NONE

Mend.io Vulnerability Database

We found results for “”

CVE-2023-51764

Good to know:

Date: December 24, 2023

Language: C

Severity Score

Related Resources (19)

Severity Score

Weakness Type (CWE)

Top Fix

Upgrade Version

CVSS v3.1

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