Postfix through 3.8.4 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: 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.
Platform | Package | Release Date | Advisory |
---|---|---|---|
Amazon Linux 1 | postfix | 2024-02-01 19:33 | ALAS-2024-1914 |
Amazon Linux 2 - Core | postfix | 2024-01-19 01:51 | ALAS2-2024-2420 |
Amazon Linux 2023 | postfix | 2024-01-19 01:31 | ALAS2023-2024-495 |
Score Type | Score | Vector | |
---|---|---|---|
Amazon Linux | CVSSv3 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
NVD | CVSSv3 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |