The advancement of technical fields always requires an adaptation of the legal system. The question of the legal nature of software has been raised for decades, yet it remains controversial and multifaceted. The author further develops this question by using it as a starting point for an investigation into liability in the event of malfunctions of software-based building security systems, demonstrating that software systems can be integrated into traditional product liability. A complementary comparative legal analysis provides a comprehensive basis for evaluating central questions of software law. Despite significantly divergent liability systems, corresponding development trends often emerge.