Software Engineer not challenged enough at work, feels like wasting my time

I work as a software engineer. I've been working at this workplace for around 2 years. But, I don't find the work challenging enough (just boring bugfixes only). Given that I spend 8 hours at my workplace, I probably do just around 3 hours of productive work. I think I am wasting my time. Is it bad if I want better work ? Should I consider this as my aversion and just continue with my work ?