From 3ecbbbd0662979fc617320dd573fd06b53fbce67 Mon Sep 17 00:00:00 2001 From: Stoiko Ivanov Date: Mon, 12 Feb 2024 21:59:59 +0100 Subject: [PATCH] templates: postfix: adapt to current default setting for smtpsmuggling postfix recently released new versions (for all supported stable versions including 3.7.10), which changed the behavior regarding bare newlines (which originally caused smtp-smuggling [0]). Instead of directly rejecting smtp sessions when is used as command separator, the session continues, however a bare is not recognized as end for the DATA command. The current setting of `smtpd_forbid_bare_newline = yes` (in 3.7.9) used to behave like the new setting of 'reject'. In 3.7.10 this was changed and it behaves like `smtpd_forbid_bare_newline = normalize` (the default for postfix > 3.9) The current patch simply adapts to the current default naming (yes is an alias for normalize) - The change in behavior came with the postfix update shipped in proposed-updates end of January and part of Debian 12.5 (released on 10.02.2024). As both versions mitigate smtp-smuggling in postfix, and even the more drastic behavior of rejecting bare did not cause any problems in our support-channels and own deployments the patch is not security-relevant. [0] https://www.postfix.org/smtp-smuggling.html [1] https://metadata.ftp-master.debian.org/changelogs//main/p/postfix/postfix_3.7.10-0+deb12u1_changelog Signed-off-by: Stoiko Ivanov --- src/templates/main.cf.in | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/templates/main.cf.in b/src/templates/main.cf.in index 434d5cd..8b4339d 100644 --- a/src/templates/main.cf.in +++ b/src/templates/main.cf.in @@ -104,7 +104,7 @@ unverified_recipient_reject_code = [% pmg.mail.verifyreceivers %] smtpd_data_restrictions = reject_unauth_pipelining -smtpd_forbid_bare_newline = yes +smtpd_forbid_bare_newline = normalize smtpd_forbid_bare_newline_exclusions = $mynetworks, cidr:/etc/postfix/clientaccess -- 2.39.2