Recently, pervasive and ubiquitous computing evolved tremendously and has become an integral part of many fields. This is widely attributed to their efficiency in integrating with everyday components and handling tasks in a faster and better way. As a result, technologies to facilitate their development, integration and security also evolved. Middleware is an essential component in this field and recently more emphasis has been put on security middleware as an enabling component for pervasive and ubiquitous applications. This is due to the high levels of personal and private data sharing in these systems. In this paper we survey some representative security middleware approaches and highlight their various properties and characteristics. We also discuss and compare these approaches in terms of their design, target environments, and main features. The review reveals that several options are available; however, there are still many issues and problems to be addressed to achieve more efficient security middleware.