libcurl cookie domain tailmatch
                        ===============================

Project cURL Security Advisory, April 12th 2013
http://curl.haxx.se/docs/security.html

1. VULNERABILITY

   libcurl is vulnerable to a cookie leak vulnerability when doing requests
   across domains with matching tails.

   When communicating over HTTP(S) and having libcurl's cookie engine enabled,
   libcurl will store and hold cookies for use when subsequent requests are
   done to hosts and paths that match those kept cookies. Due to a bug in the
   tailmatching function, libcurl could wrongly send cookies meant for the
   domain 'ample.com' when communicating with 'example.com'.

   This vulnerability can be used to hijack sessions in targetted attacks since
   registering domains using a known domain's name as an ending is trivial.

   Both curl the command line tool and applications using the libcurl library
   are vulnerable.

   There are no known exploits available at this time.

   The Common Vulnerabilities and Exposures (CVE) project has assigned the name
   CVE-2013-1944 to this issue.

2. AFFECTED VERSIONS

   Affected versions: all versions to and including 7.29.0
   Not affected versions: curl >= 7.30.0

   libcurl is used by many applications, but not always advertised as such!

3. THE SOLUTION

   libcurl 7.30.0 implements the function properly and will not send cookies to
   sites just because the host names use the same tail.

4. RECOMMENDATIONS

   We suggest you take one of the following actions immediately, in order of
   preference:

   A - Upgrade to curl and libcurl 7.30.0

   B - Apply this patch and rebuild libcurl

       http://curl.haxx.se/curl-tailmatch.patch

   C - Disable use of cookies or HTTP entirely in your application

5. TIME LINE

   Vulnerability found and patched by YAMADA Yasuharu.

   It was reported (publicly) to the curl project on April 9th 2013.

   curl 7.30.0 was released on April 12th 2013, coordinated with the
   publication of this advisory.

6. CREDITS

   Reported and fixed by YAMADA Yasuharu. Thanks a lot!

-- 
  / daniel.haxx.se
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