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Fix CVE-2017-16944:
https://bugs.exim.org/show_bug.cgi?id=2201
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-16944
Patch copied from upstream source repository:
https://git.exim.org/exim.git/commit/4804c62909a62a3ac12ec4777ebd48c541028965
From 4804c62909a62a3ac12ec4777ebd48c541028965 Mon Sep 17 00:00:00 2001
From: "Heiko Schlittermann (HS12-RIPE)" <hs@schlittermann.de>
Date: Mon, 27 Nov 2017 22:42:33 +0100
Subject: [PATCH] Chunking: do not treat the first lonely dot special.
CVE-2017-16944, Bug 2201
(cherry picked from commit 178ecb70987f024f0e775d87c2f8b2cf587dd542)
Change log update
(cherry picked from commit b488395f4d99d44a950073a64b35ec8729102782)
---
doc/doc-txt/ChangeLog | 6 +++++-
src/src/receive.c | 2 +-
src/src/smtp_in.c | 7 +++++++
3 files changed, 13 insertions(+), 2 deletions(-)
#diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
#index a2d9339..541ebaf 100644
#--- a/doc/doc-txt/ChangeLog
#+++ b/doc/doc-txt/ChangeLog
#@@ -61,7 +61,11 @@ JH/30 Fix a logging bug on aarch64: an unsafe routine was previously used for
#
# JH/34 Bug 2199: fix a use-after-free while reading smtp input for header lines.
# A crafted sequence of BDAT commands could result in in-use memory beeing
#- freed.
#+ freed. CVE-2017-16943.
#+
#+HS/03 Bug 2201: Fix checking for leading-dot on a line during headers reading
#+ from SMTP input. Previously it was always done; now only done for DATA
#+ and not BDAT commands. CVE-2017-16944.
#
#
# Exim version 4.89
diff --git a/src/src/receive.c b/src/src/receive.c
index 20672db..2812ea2 100644
--- a/src/receive.c
+++ b/src/receive.c
@@ -1827,7 +1827,7 @@ for (;;)
prevent further reading), and break out of the loop, having freed the
empty header, and set next = NULL to indicate no data line. */
- if (ptr == 0 && ch == '.' && (smtp_input || dot_ends))
+ if (ptr == 0 && ch == '.' && dot_ends)
{
ch = (receive_getc)(GETC_BUFFER_UNLIMITED);
if (ch == '\r')
diff --git a/src/src/smtp_in.c b/src/src/smtp_in.c
index 1b45f84..0207540 100644
--- a/src/smtp_in.c
+++ b/src/smtp_in.c
@@ -4955,16 +4955,23 @@ while (done <= 0)
DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n",
(int)chunking_state, chunking_data_left);
+ /* push the current receive_* function on the "stack", and
+ replace them by bdat_getc(), which in turn will use the lwr_receive_*
+ functions to do the dirty work. */
lwr_receive_getc = receive_getc;
lwr_receive_ungetc = receive_ungetc;
+
receive_getc = bdat_getc;
receive_ungetc = bdat_ungetc;
+ dot_ends = FALSE;
+
goto DATA_BDAT;
}
case DATA_CMD:
HAD(SCH_DATA);
+ dot_ends = TRUE;
DATA_BDAT: /* Common code for DATA and BDAT */
if (!discarded && recipients_count <= 0)
--
1.9.1
|
