Amazon Linux AMI Security Advisory: ALAS-2012-65
Advisory Release Date: 2014-09-14 15:46 Pacific
Two integer overflow flaws, leading to heap-based buffer overflows, were found in the way libtiff attempted to allocate space for a tile in a TIFF image file. An attacker could use these flaws to create a specially-crafted TIFF file that, when opened, would cause an application linked against libtiff to crash or, possibly, execute arbitrary code. (CVE-2012-1173 )
Run yum update libtiff to update your system.