Software-Defined Networking (SDN) is a new approach that aims to virtualize networking by decoupling data plan from the control plan. As this approach influenced many actors in the networking community because of its agility, programmability and central management. Many questions have been raised about issues that come with it. One of the biggest concerns related to SDN is security, this aspect is fundamental when deciding to adopt SDN as a solution or not. Security threats are targeting the application layer, control layer, and data layer. In this paper, we propose a new mechanism called “SOLID-FLOW” to enhance flow rules database integrity within the SDN controller. First, we discuss security threats related to SDN mechanisms regarding the control layer, and then we debate appropriate solutions that have been presented in the literature to address security related issues. Finally, we present our new mechanism.