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01 Record

CVE-2023-51764

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

UnratedPUBLISHEDCNA: mitre
CNA base scoreUnratedNo CNA CVSS vector
View raw JSON

02 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

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
2.63% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 85.4% of scored records. A rank, not a probability.
NVD base score
5.3 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD analysis status
Modified. NVD last modified this record on 2026-10-08.
Red Hat severity
Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2023-12-24 00:00Z2 YR AGO
Last updated
2026-10-08 21:03Z21 DAYS AGO
Reserved
2023-12-24
Assigning CNA
mitre
Record state
PUBLISHED
Severity
Not rated by the issuing CNA
CNA CVSS vector
Not published by the issuing CNA
Weaknesses
  • CWE-345Insufficient Verification of Data AuthenticityClass
Data version
5.2
Document digest
ac9496fe93444c2c902c44c02d80e6028b6389b3e7b695f35bc6c77a568cc2e6

05 Affected products

VendorProductVersionsPlatforms
fedoraprojectfedoraNot specified—
postfixpostfixNot specified—
redhatenterprise_linuxNot specified—

06 References

07 Fixed in

AlmaLinux 9

  • postfix
    Fixed in 2:3.5.25-1.el9
  • postfix-cdb
    Fixed in 2:3.5.25-1.el9
  • postfix-ldap
    Fixed in 2:3.5.25-1.el9
  • postfix-lmdb
    Fixed in 2:3.5.25-1.el9
  • postfix-mysql
    Fixed in 2:3.5.25-1.el9
  • postfix-pcre
    Fixed in 2:3.5.25-1.el9
  • postfix-perl-scripts
    Fixed in 2:3.5.25-1.el9
  • postfix-pgsql
    Fixed in 2:3.5.25-1.el9
  • postfix-sqlite
    Fixed in 2:3.5.25-1.el9

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 9

  • postfix
    Fixed in 2:3.5.25-1.el9
  • postfix-cdb
    Fixed in 2:3.5.25-1.el9
  • postfix-ldap
    Fixed in 2:3.5.25-1.el9
  • postfix-lmdb
    Fixed in 2:3.5.25-1.el9
  • postfix-mysql
    Fixed in 2:3.5.25-1.el9
  • postfix-pcre
    Fixed in 2:3.5.25-1.el9
  • postfix-perl-scripts
    Fixed in 2:3.5.25-1.el9
  • postfix-pgsql
    Fixed in 2:3.5.25-1.el9
  • postfix-sqlite
    Fixed in 2:3.5.25-1.el9

Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Debian 12

  • postfix
    Fixed in 3.7.9-0+deb12u1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • postfix
    Fixed in 3.8.4-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • postfix
    Fixed in 3.8.4-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 20.04 LTS

  • postfix
    Fixed in 3.4.13-0ubuntu1.4

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 22.04 LTS

  • postfix
    Fixed in 3.6.4-1ubuntu1.3

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 14.04 LTS

  • postfix
    Fixed in 2.11.0-1ubuntu1.2+esm3
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 16.04 LTS

  • postfix
    Fixed in 3.1.0-3ubuntu0.4+esm3
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 18.04 LTS

  • postfix
    Fixed in 3.3.0-1ubuntu0.4+esm3
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.