With the increasing importance of IT security in society and economy, the need to train computer science students in IT security is becoming more and more important. In the process of developing a new IT security undergraduate course, it was found that the current training concepts used in existing master courses were not suitable as it was too much effort for the undergraduate students to set up their own practical exercise environments. To remedy this problem we have built a web-based exercise platform for IT security training using Docker containers. This enables the students to easily use prebuilt exercise environments specifically designed for the new course. The platform was evaluated during the winter semester 2020/21 through a small survey among the students. The feedback indicated that the platform is convenient to use and helped the students during the course and in exam preparation.