An Efficient Vulnerability Detection Method for 5G NAS Protocol Based on Combinatorial Testing

With the rapid development and wide application of 5G networks, the security of 5G networks has become a widely concerned issue. Protocol security is the foundation of 5G network security. To protect 5G protocol security, we propose an efficient vulnerability detection method for 5G NAS protocol. In this work, we use a combinatorial testing algorithm to generate testing cases, which can detect the vulnerability caused by multi-parameter interaction. Furthermore, we define compliance constraints and semantic constraints to restrict the scale of input space and maximize the effectiveness of the testing cases. Finally, we implement a prototype system based on this method and then conduct practical vulnerability detection on 5G UE simulation environments UERANSIM and srsUE. Through experiments, we find five security vulnerabilities having both security and privacy implications and prove that our method has better performance in terms of protocol state coverage and the scale of testing cases.