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[SECURITY ADVISORY] cookie leak for TLDs

From: Daniel Stenberg <daniel_at_haxx.se>
Date: Wed, 10 Sep 2014 08:40:48 +0200 (CEST)

                          libcurl cookie leak for TLDs
                          ============================

Project cURL Security Advisory, September 10th 2014
http://curl.haxx.se/docs/security.html

1. VULNERABILITY

   libcurl wrongly allows cookies to be set for Top Level Domains (TLDs), thus
   making them apply broader than cookies are allowed. This can allow arbitrary
   sites to set cookies that then would get sent to a different and unrelated
   site or domain.

2. INFO

   Cookie parsing and use is opt-in by applications and is not enabled by
   default.

   libcurl's cookie parser has no Public Suffix awareness, so apart from
   rejecting TLDs from being allowed it might still allow cookies for domains
   that are otherwise widely rejected by ordinary browsers. See
   https://publicsuffix.org/ for details.

   The Common Vulnerabilities and Exposures (CVE) project has assigned the name
   CVE-2014-3620 to this issue.

3. AFFECTED VERSIONS

   Affected versions: from libcurl 7.31.0 to and including 7.37.1
   Not affected versions: libcurl < 7.31.0 and libcurl >= 7.38.0

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

4. THE SOLUTION

   libcurl 7.38.0 doesn't accept cookies set for just a TLD. Note that it does
   not add any public suffix awareness apart from that.

   A patch for this problem is available at:

     http://curl.haxx.se/CVE-2014-3620.patch

5. RECOMMENDATIONS

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

   A - Upgrade to curl and libcurl 7.38.0

   B - Apply the patch and rebuild libcurl

   C - Avoid using cookies in your application

6. TIME LINE

   It was reported to the curl project on August 15th 2014. We contacted
   distros_at_openwall on September 1st.

   libcurl 7.38.0 was released on September 10th 2014, coordinated with the
   publication of this advisory.

7. CREDITS

   Reported by Tim Ruehsen. Patch written by Daniel Stenberg.

   Thanks a lot!

-- 
  / daniel.haxx.se
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Received on 2014-09-10