FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

cURL -- multiple vulnerabilities

Affected packages
curl < 7.42.0

Details

VuXML ID 6294f75f-03f2-11e5-aab1-d050996490d0
Discovery 2015-04-22
Entry 2015-05-26

cURL reports:

libcurl keeps a pool of its last few connections around after use to fascilitate easy, conventient and completely transparent connection re-use for applications.

When doing HTTP requests NTLM authenticated, the entire connnection becomes authenticated and not just the specific HTTP request which is otherwise how HTTP works. This makes NTLM special and a subject for special treatment in the code. With NTLM, once the connection is authenticated, no further authentication is necessary until the connection gets closed.

When doing HTTP requests Negotiate authenticated, the entire connnection may become authenticated and not just the specific HTTP request which is otherwise how HTTP works, as Negotiate can basically use NTLM under the hood. curl was not adhering to this fact but would assume that such requests would also be authenticated per request.

libcurl supports HTTP "cookies" as documented in RFC 6265. Together with each individual cookie there are several different properties, but for this vulnerability we focus on the associated "path" element. It tells information about for which path on a given host the cookies is valid.

The internal libcurl function called sanitize_cookie_path() that cleans up the path element as given to it from a remote site or when read from a file, did not properly validate the input. If given a path that consisted of a single double-quote, libcurl would index a newly allocated memory area with index -1 and assign a zero to it, thus destroying heap memory it wasn't supposed to.

There is a private function in libcurl called fix_hostname() that removes a trailing dot from the host name if there is one. The function is called after the host name has been extracted from the URL libcurl has been told to act on.

If a URL is given with a zero-length host name, like in "http://:80" or just ":80", fix_hostname() will index the host name pointer with a -1 offset (as it blindly assumes a non-zero length) and both read and assign that address.

References

CVE Name CVE-2014-3143
CVE Name CVE-2014-3144
CVE Name CVE-2014-3145
CVE Name CVE-2014-3148
URL http://curl.haxx.se/docs/adv_20150422A.html
URL http://curl.haxx.se/docs/adv_20150422B.html
URL http://curl.haxx.se/docs/adv_20150422C.html
URL http://curl.haxx.se/docs/adv_20150422D.html