CURL-CVE-2014-3613

cookie leak with IP address as domain

By not detecting and rejecting domain names for partial literal IP addresses properly when parsing received HTTP cookies, libcurl can be fooled to both sending cookies to wrong sites and into allowing arbitrary sites to set cookies for others. For this problem to trigger, the client application must use the numerical IP address in the URL to access the site and the site must send back cookies to the site using domain= and a partial IP address. Since libcurl wrongly approaches the IP address like it was a normal domain name, a site at IP address `192.168.0.1` can set cookies for anything ending with `.168.0.1` thus fooling libcurl to send them also to for example `129.168.0.1`. The flaw requires dots to be present in the IP address, which restricts the flaw to IPv4 literal addresses or IPv6 addresses using the somewhat unusual "dotted-quad" style: `::ffff:192.0.2.128`. This is not believed to be done by typical sites as this is not supported by clients that adhere to the rules of the RFC 6265, and many sites are written to explicitly use their own specific named domain when sending cookies.