Amazon Linux AMI Security Advisory: ALAS-2012-143
Advisory Release Date: 2014-09-14 17:18 Pacific
A heap-based buffer underflow flaw was found in the way libxml2 decoded certain entities. A remote attacker could provide a specially-crafted XML file that, when opened in an application linked against libxml2, would cause the application to crash or, potentially, execute arbitrary code with the privileges of the user running the application. (CVE-2012-5134 )
Run yum update libxml2 to update your system.