Upgrade the RouterOS, “…It’s running v6.39.2”
Depending which config you want to go, i.e. Bridge port or Master-Slave port config, upgrade to at least the following versions:
Bridge = 6.42.3
Master-Slave = 6.40.8
See link below for vulnerability info:
http://forum.mikrotik.com/t/winbox-vulnerability-please-upgrade/122004/1