Amazon Linux AMI Security Advisory: ALAS-2016-659
Advisory Release Date: 2016-03-10 16:30 Pacific
A use-after-free flaw related to the PMAP_CALLIT operation and TCP/UDP connections was discovered in rpcbind. A remote, unauthenticated attacker could possibly exploit this flaw to crash the rpcbind service (denial of service) by performing a series of UDP and TCP calls.
Run yum update rpcbind to update your system.