Why security features are missing in my WSO2 DSS?
Do I need to install a feature? If yes, which one?
AFAIR the security features are now moved to Developer Studio. You can use Developer Studio to achieve those features. You may refer webinar in [1] which is for WSO2 ESB 4.9.0
[1] - http://wso2.com/library/webinars/2015/12/how-to-secure-your-enterprise-services-with-wso2-esb-4.9/