Vulnerability Monitor

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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 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.


Published

2023-12-24T05:15:08.273

Last Modified

2024-11-21T08:38:44.733

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 5.3 (MEDIUM)

Weaknesses
  • Type: Primary
    CWE-345

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application postfix postfix < 3.5.23 Yes
Application postfix postfix < 3.6.13 Yes
Application postfix postfix < 3.7.9 Yes
Application postfix postfix < 3.8.4 Yes
Operating System fedoraproject fedora 38 Yes
Operating System fedoraproject fedora 39 Yes
Operating System redhat enterprise_linux 8.0 Yes
Operating System redhat enterprise_linux 9.0 Yes

References