How competitive are MBB internships for undergraduates? How much is expected?

I am currently on my second year of my Mathematics Bachelor at Technical University of Munich and I would like to apply for an MBB internship as an undergraduate in Munich. I don't have an MBA or any official financial/business education and all my business/finance knowledge is self-taught. How much of a problem is this for an undergraduate internship? How much is expected/required? On another note, how does the recruiting process for undergraduates differ from the recruiting process for PHDs/MBAs? Is it just the complexity of the cases and different expectations or is there anything else?