From 3604fde3d3c9b0d0e389e079aecf470d123ba180 Mon Sep 17 00:00:00 2001
From: YAMADA Yasuharu <[email protected]>
Date: Thu, 11 Apr 2013 00:17:15 +0200
Subject: [PATCH] cookie: fix tailmatching to prevent cross-domain leakage
Cookies set for 'example.com' could accidentaly also be sent by libcurl
to the 'bexample.com' (ie with a prefix to the first domain name).
This is a security vulnerabilty, CVE-2013-1944.
Bug: http://curl.haxx.se/docs/adv_20130412.html
--- lib/cookie.c 2013-04-12 13:42:43.099608542 -0700
+++ lib/cookie.c 2013-04-12 13:51:27.701845050 -0700
@@ -118,15 +118,29 @@
free(co);
}
-static bool tailmatch(const char *little, const char *bigone)
+static bool tailmatch(const char *cooke_domain, const char *hostname)
{
- size_t littlelen = strlen(little);
- size_t biglen = strlen(bigone);
+ size_t cookie_domain_len = strlen(cooke_domain);
+ size_t hostname_len = strlen(hostname);
- if(littlelen > biglen)
+ if(hostname_len < cookie_domain_len)
return FALSE;
- return Curl_raw_equal(little, bigone+biglen-littlelen) ? TRUE : FALSE;
+ if(!Curl_raw_equal(cooke_domain, hostname+hostname_len-cookie_domain_len))
+ return FALSE;
+
+ /* A lead char of cookie_domain is not '.'.
+ RFC6265 4.1.2.3. The Domain Attribute says:
+ For example, if the value of the Domain attribute is
+ "example.com", the user agent will include the cookie in the Cookie
+ header when making HTTP requests to example.com, www.example.com, and
+ www.corp.example.com.
+ */
+ if(hostname_len == cookie_domain_len)
+ return TRUE;
+ if('.' == *(hostname + hostname_len - cookie_domain_len - 1))
+ return TRUE;
+ return FALSE;
}
/*