To Fix Run
yum update
as soon as possible!
Here is the Bug Report:
https://securityblog.redhat.com/2014/09/24/bash-specially-crafted-environment-variables-code-injection-attack/
Links to the actual Centos Bash updates:
CentOS-5:
http://lists.centos.org/pipermail/centos-announce/2014-September/020582.html
CentOS-6:
http://lists.centos.org/pipermail/centos-announce/2014-September/020585.html
CentOS-7:
http://lists.centos.org/pipermail/centos-announce/2014-September/020583.html
SOLVED: Virtualmin CentOS 5/6/7 Linux Bash Bug – Critical update