I want to buy a used docking station for my laptop. Has there ever been a case of a docking station being a security concern?

I found a used docking station for my Dell laptop. The price is very interesting and the docking station seems to be in perfect shape. But I’m somehow worried about potential security risks. After all, you could install some kind of keylogger in the station’s firmware. Am I being paranoid here or is it possible in any way?