You can do this with Srendarr's (IIRC?) and also Bandits UI (you need to make the debuffs into a widget (middle mouse button to add to widget list) and then you can display them on the screen).
Srendarr Buff & Debuff Tracker
Bandits UI
My personal favourite is Bandit's but mainly because it has everything I need - mini-map, timers, unit frames etc etc