As Software-Defined Networking (SDN) is getting popular, its security issue is being magnified as a new controversy, and this trend can be found from recent studies of presenting possible security vulnerabilities in SDN. Understanding the attack surface of SDN is necessary, and it is the starting point to make it more secure. However, most existing studies depend on empirical methods in different environments, and thus they have stopped short of converging on a systematic methodology or developing automated systems to rigorously test for security flaws in SDNs. Therefore, we need to disclose any possible attack scenarios in diverse SDN environments and examine how these attacks operate in those environments. Inspired by the necessity for disclosing the vulnerabilities in diverse SDN operating scenarios, we suggest an SDN penetration tool, DELTA, to regenerate known attack scenarios in diverse test cases. Furthermore, DELTA can even provide a chance of discovering unknown security problems in SDN by employing a fuzzing module. In our evaluation, DELTA successfully reproduced 26 known attack scenarios, across diverse SDN controller environments, and also discovered 9 novel SDN application mislead attacks.

Introduction

Security has been a subject of controversy in many newly emerged networked systems, such as peer-to-peer networks and cloud networks. After their appearance, researchers and practitioners have examined their security issues from various angles to verify their safeness, and this process makes them more secure so that they can be adapted in a real-world system. Software-Defined Networking (SDN), which manages a network in a centralized way, is a recently proposed networking technology, and now it is endorsed by both industry and academia. As SDN technology is getting popular, its security problem is being at issue, and thus researchers are investigating its security issues as they have conducted in other networked systems [26, 46, 39, 20, 25, 1]. Such security-critical reviews of SDNs offer a view into various breaches, but overall, the attack surfaces thus far explored have been quite limited to either highly targeted exploits, such as ARP spoofing or specific vulnerabilities that arise in various SDN components. Each previous result may not be applicable to other SDN environments (e.g., different control planes). Hence, operators seeking to assess security issues in their SDN environments need to survey existing SDN security-related studies and determine relevance on a case-by-case basis. Furthermore, an operator may have to adapt or redesign deployment-specific security test suites. This paper introduces a new SDN security evaluation framework, called DELTA, which can automatically instan- ∗Corresponding author ORCID(s): tiate attack cases against SDN elements across diverse environments, and which may assist in uncovering unknown security problems within an SDN deployment. Motivated by security testing tools in the traditional network security domain [45, 15], DELTA represents the first security assessment tool for SDN environments. Furthermore, we enhanced our tool with a specialized fuzzing module [30] to exploit opportunities for discovering unknown security flaws in SDNs.