mutt/SOURCES/0017-CVE-2023-4875-Check-for-NULL-userhdrs.patch

48 lines
1.7 KiB
Diff

From 74b4833b56212dbbac6f6353f6989f91176671a2 Mon Sep 17 00:00:00 2001
From: Kevin McCarthy <kevin@8t8.us>
Date: Mon, 4 Sep 2023 12:50:07 +0800
Subject: [PATCH] (CVE-2023-4875) Check for NULL userhdrs.
When composing an email, miscellaneous extra headers are stored in a
userhdrs list. Mutt first checks to ensure each header contains at
least a colon character, passes the entire userhdr field (name, colon,
and body) to the rfc2047 decoder, and safe_strdup()'s the result on
the userhdrs list. An empty result would from the decode would result
in a NULL headers being added to list.
The previous commit removed the possibility of the decoded header
field being empty, but it's prudent to add a check to the strchr
calls, in case there is another unexpected bug resulting in one.
Thanks to Chenyuan Mi (@morningbread) for discovering the two strchr
crashes, giving a working example draft message, and providing the
stack traces for the two NULL derefences.
(cherry picked from commit 4cc3128abdf52c615911589394a03271fddeefc6)
---
sendlib.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/sendlib.c b/sendlib.c
index 8569e5cf..007baac1 100644
--- a/sendlib.c
+++ b/sendlib.c
@@ -2318,7 +2318,7 @@ int mutt_write_rfc822_header (FILE *fp, ENVELOPE *env, BODY *attach, char *date,
/* Add any user defined headers */
for (; tmp; tmp = tmp->next)
{
- if ((p = strchr (tmp->data, ':')))
+ if ((p = strchr (NONULL (tmp->data), ':')))
{
q = p;
@@ -2366,7 +2366,7 @@ static void encode_headers (LIST *h)
for (; h; h = h->next)
{
- if (!(p = strchr (h->data, ':')))
+ if (!(p = strchr (NONULL (h->data), ':')))
continue;
i = p - h->data;