1 From 3604fde3d3c9b0d0e389e079aecf470d123ba180 Mon Sep 17 00:00:00 2001

     2 From: YAMADA Yasuharu <[email protected]>

     3 Date: Thu, 11 Apr 2013 00:17:15 +0200

     4 Subject: [PATCH] cookie: fix tailmatching to prevent cross-domain leakage

     5 

     6 Cookies set for 'example.com' could accidentaly also be sent by libcurl

     7 to the 'bexample.com' (ie with a prefix to the first domain name).

     8 

     9 This is a security vulnerabilty, CVE-2013-1944.

    10 

    11 Bug: http://curl.haxx.se/docs/adv_20130412.html

    12 

    13 --- lib/cookie.c.orig	2013-11-18 14:05:59.517749330 -0800

    14 +++ lib/cookie.c	2013-11-18 14:08:09.852442022 -0800

    15 @@ -122,15 +122,29 @@

    16    free(co);

    17  }

    18  

    19 -static bool tailmatch(const char *little, const char *bigone)

    20 +static bool tailmatch(const char *cooke_domain, const char *hostname)

    21  {

    22 -  size_t littlelen = strlen(little);

    23 -  size_t biglen = strlen(bigone);

    24 +  size_t cookie_domain_len = strlen(cooke_domain);

    25 +  size_t hostname_len = strlen(hostname);

    26  

    27 -  if(littlelen > biglen)

    28 +  if(hostname_len < cookie_domain_len)

    29      return FALSE;

    30  

    31 -  return (bool)Curl_raw_equal(little, bigone+biglen-littlelen);

    32 +  if(!Curl_raw_equal(cooke_domain, hostname+hostname_len-cookie_domain_len))

    33 +    return FALSE;

    34 +

    35 +  /* A lead char of cookie_domain is not '.'.

    36 +     RFC6265 4.1.2.3. The Domain Attribute says:

    37 +       For example, if the value of the Domain attribute is

    38 +       "example.com", the user agent will include the cookie in the Cookie

    39 +       header when making HTTP requests to example.com, www.example.com, and

    40 +       www.corp.example.com.

    41 +   */

    42 +  if(hostname_len == cookie_domain_len)

    43 +    return TRUE;

    44 +  if('.' == *(hostname + hostname_len - cookie_domain_len - 1))

    45 +    return TRUE;

    46 +  return FALSE;

    47  }

    48  

    49  /*