CURL-CVE-2015-3144

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

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

At best, this gets unnoticed but can also lead to a crash or worse. We have not researched further what kind of malicious actions that potentially this could be used for.