Analysis of QoS Degradation Attacks in Multi-Slice Containerized 5G Core Networks

5G mobile networks aim to achieve ultra-low latency, high reliability, and support for diverse services through a cloud-native, service-oriented architecture. A key innovation in 5G is the introduction of Network Slicing (NS), which enables customized Quality of Service (QoS) for various use cases, with each slice independently configured and managed. While prior research has implemented 5G core and slicing environments using virtual machines or containers, few studies have incorporated standardized 5G QoS characteristics and slice types into actual implementations. This study presents a container-based 5G NS environment that maps slice service types to 5G performance requirements and standardized QoS characteristics. The environment is experimentally validated to ensure that each network function meets its QoS constraints, offering a realistic platform for evaluating 5G security threats. Furthermore, we design and implement QoS degradation attacks in this setup, simulating a malicious Session Management Function to demonstrate how session manipulation can disrupt QoS in the absence of strong core authentication mechanisms. These results highlight the urgent need for improved security to protect QoS in future 5G NS environments.