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Debian: CVE-2023-51764: postfix -- security update

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Debian: CVE-2023-51764: postfix -- security update

Severity
4
CVSS
(AV:L/AC:M/Au:N/C:P/I:P/A:P)
Published
12/24/2023
Created
02/06/2024
Added
02/05/2024
Modified
02/05/2024

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.

Solution(s)

  • debian-upgrade-postfix

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