Improper Enforcement of Message Integrity During Transmission in a Communication Channel Affecting vdukhovni/postfix package, versions [,3.5.23)[3.6.0-RC1,3.6.13)[3.7.0-RC1,3.7.9)[3.8.0-RC1,3.8.4)


Severity

Recommended
0.0
high
0
10

CVSS assessment by Snyk's Security Team. Learn more

Threat Intelligence

Exploit Maturity
Proof of Concept
EPSS
2.64% (85th percentile)

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  • Snyk IDSNYK-UNMANAGED-VDUKHOVNIPOSTFIX-6139276
  • published25 Dec 2023
  • disclosed24 Dec 2023
  • creditSEC Consult

Introduced: 24 Dec 2023

CVE-2023-51764  (opens in a new tab)
CWE-924  (opens in a new tab)

How to fix?

Upgrade vdukhovni/postfix to version 3.5.23, 3.6.13, 3.7.9, 3.8.4 or higher.

Overview

Affected versions of this package are vulnerable to Improper Enforcement of Message Integrity During Transmission in a Communication Channel due to improper handling of SMTP protocol sequences, which allows header smuggling. An attacker can inject e-mail messages that appear to originate from the server, thus bypassing SPF protection mechanisms by exploiting the support for <LF>.<CR><LF> sequences, which are not universally handled by other e-mail servers. This is only exploitable if smtpd_data_restrictions is not configured with reject_unauth_pipelining or other protective options available in recent versions.

Workaround

This vulnerability can be mitigated by configuring smtpd_data_restrictions with reject_unauth_pipelining or by setting smtpd_forbid_bare_newline to yes after upgrading.

CVSS Base Scores

version 3.1