From 8a6d9ded5f02f0294ae63a007e26087316c1998e Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <[email protected]>
Date: Tue, 4 Oct 2016 16:59:38 +0200
Subject: [PATCH] parsedate: handle cut off numbers better
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

... and don't read outside of the given buffer!

CVE-2016-8621

bug: https://curl.haxx.se/docs/adv_20161102G.html
Reported-by: Luật Nguyễn
---
 lib/parsedate.c        | 12 +++++++-----
 tests/data/test517     |  6 ++++++
 tests/libtest/lib517.c |  8 +++++++-
 3 files changed, 20 insertions(+), 6 deletions(-)

--- lib/parsedate.c
+++ lib/parsedate.c
@@ -3,11 +3,11 @@
  *  Project                     ___| | | |  _ \| |
  *                             / __| | | | |_) | |
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2014, Daniel Stenberg, <[email protected]>, et al.
+ * Copyright (C) 1998 - 2016, Daniel Stenberg, <[email protected]>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
  * are also available at https://curl.haxx.se/docs/copyright.html.
  *
@@ -384,19 +384,21 @@ static int parsedate(const char *date, time_t *output)
     }
     else if(ISDIGIT(*date)) {
       /* a digit */
       int val;
       char *end;
+      int len=0;
       if((secnum == -1) &&
-         (3 == sscanf(date, "%02d:%02d:%02d", &hournum, &minnum, &secnum))) {
+         (3 == sscanf(date, "%02d:%02d:%02d%n",
+                      &hournum, &minnum, &secnum, &len))) {
         /* time stamp! */
-        date += 8;
+        date += len;
       }
       else if((secnum == -1) &&
-              (2 == sscanf(date, "%02d:%02d", &hournum, &minnum))) {
+              (2 == sscanf(date, "%02d:%02d%n", &hournum, &minnum, &len))) {
         /* time stamp without seconds */
-        date += 5;
+        date += len;
         secnum = 0;
       }
       else {
         long lval;
         int error;
--- tests/data/test517
+++ tests/data/test517
@@ -114,10 +114,16 @@ nothing
 79: 20110632 12:34:56 => -1
 80: 20110623 56:34:56 => -1
 81: 20111323 12:34:56 => -1
 82: 20110623 12:34:79 => -1
 83: Wed, 31 Dec 2008 23:59:60 GMT => 1230768000
+84: 20110623 12:3 => 1308830580
+85: 20110623 1:3 => 1308790980
+86: 20110623 1:30 => 1308792600
+87: 20110623 12:12:3 => 1308831123
+88: 20110623 01:12:3 => 1308791523
+89: 20110623 01:99:30 => -1
 </stdout>
 
 # This test case previously tested an overflow case ("2094 Nov 6 =>
 # 2147483647") for 32bit time_t, but since some systems have 64bit time_t and
 # handles this (returning 3939840000), and some 64bit-time_t systems don't
--- tests/libtest/lib517.c
+++ tests/libtest/lib517.c
@@ -3,11 +3,11 @@
  *  Project                     ___| | | |  _ \| |
  *                             / __| | | | |_) | |
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2011, Daniel Stenberg, <[email protected]>, et al.
+ * Copyright (C) 1998 - 2016, Daniel Stenberg, <[email protected]>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
  * are also available at https://curl.haxx.se/docs/copyright.html.
  *
@@ -114,10 +114,16 @@ static const char * const dates[]={
   "20110632 12:34:56",
   "20110623 56:34:56",
   "20111323 12:34:56",
   "20110623 12:34:79",
   "Wed, 31 Dec 2008 23:59:60 GMT", /* leap second */
+  "20110623 12:3",
+  "20110623 1:3",
+  "20110623 1:30",
+  "20110623 12:12:3",
+  "20110623 01:12:3",
+  "20110623 01:99:30",
   NULL
 };
 
 int test(char *URL)
 {
-- 
2.9.3