The apartment I moved into has a kitchen with cabinets as most kitchens do. I noticed that in the mornings it has been especially cold in the kitchen, and I traced the cold air to a large gap in the corner of one of the cabinets.
The photo below was taken inside the corner cabinet. You can see a pipe exposed. A lot of cold air is seeping in through here.
What simple things can I do (without involving the slow-moving elderly landlord) to patch this up and minimize the amount of cold air that gets in?