From 23a41dae4ddb3c5ae48f90e03b67653881f93018 Mon Sep 17 00:00:00 2001 From: Vsevolod Stakhov Date: Mon, 13 May 2019 11:36:20 +0100 Subject: [PATCH] [Minor] Change the default list of oversigned headers Trivia: `Subject` header needs to be oversigned as an attacker could add some 'bad' subject to DKIM signed emails with no subject (rare but possible case). This header is clearly displayed to a user hence, its presence as well as absence MUST be oversigned explicitly. `Reply-To` header is widely used to designate a special address used for replies only but not for authentication checks. It is thus possible to add a malicious `Reply-To` header to force users to reply to a DKIM signed email to some attacker's controlled email address. It clearly opens surface for social engineering like attacks and this header must thus be unconditionally oversigned even if not presented in an original message. Issue: #2887 --- src/plugins/dkim_check.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/plugins/dkim_check.c b/src/plugins/dkim_check.c index 6ad748454..0cfea3f92 100644 --- a/src/plugins/dkim_check.c +++ b/src/plugins/dkim_check.c @@ -54,13 +54,13 @@ static const gchar *M = "rspamd dkim plugin"; static const gchar default_sign_headers[] = "" - "(o)from:(x)sender:(x)reply-to:(x)subject:(x)date:(x)message-id:" + "(o)from:(x)sender:(o)reply-to:(o)subject:(x)date:(x)message-id:" "(o)to:(o)cc:(x)mime-version:(x)content-type:(x)content-transfer-encoding:" "resent-to:resent-cc:resent-from:resent-sender:resent-message-id:" "(x)in-reply-to:(x)references:list-id:list-help:list-owner:list-unsubscribe:" "list-subscribe:list-post:(x)openpgp:(x)autocrypt"; static const gchar default_arc_sign_headers[] = "" - "(o)from:(x)sender:(x)reply-to:(x)subject:(x)date:(x)message-id:" + "(o)from:(x)sender:(o)reply-to:(o)subject:(x)date:(x)message-id:" "(o)to:(o)cc:(x)mime-version:(x)content-type:(x)content-transfer-encoding:" "resent-to:resent-cc:resent-from:resent-sender:resent-message-id:" "(x)in-reply-to:(x)references:list-id:list-help:list-owner:list-unsubscribe:" -- 2.39.5