Amazon Linux AMI Security Advisory: ALAS-2014-407
Advisory Release Date: 2014-09-17 21:45 Pacific
Advisory Updated Date: 2014-09-19 12:07 Pacific
libcurl wrongly allows cookies to be set for TLDs, thus making them much broader then they are supposed to be allowed to. This can allow arbitrary sites to set cookies that then would get sent to a different and unrelated site or 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.
Run yum update curl to update your system.