Improper Interaction Between Multiple Correctly-Behaving Entities

An interaction error occurs when two entities have correct behavior when running independently of each other, but when they are integrated as components in a larger system or process, they introduce incorrect behaviors that may cause resultant weaknesses.

When a system or process combines multiple independent components, this often produces new, emergent behaviors at the system level. However, if the interactions between these components are not fully accounted for, some of the emergent behaviors can be incorrect or even insecure.