Security concerns of composite systems

For last couple of days I managed to read a bit about composite systems and how useful the component based Software Engineering when it comes to the industry. The flexibility of coupling and decoupling components in a composite systems and reusability of using one component in a number of such systems makes them very attracted in numerous applications.
But at the same time we have to consider about the security concerns in that approach. These concerns can be divided into two categories.

1.Security concerns of the component
2.Security concerns when the component is inegrated and used

When forming or modifying composite systems by coupling and decoupling different components the integrator has to evaluate how the component is secured itself. In other words how securely the component is being built by the developer.
Also the integrator has to evaluate how the system is secured from the components. A set of secure components doesn’t always guarantee a secure system. The integrator has to determine for what extent the system can trust the component.
This brings us to the topic of Trust Management in component based software engineering.