I think the stock bumpers on these trucks are rated for something like 3000 lbs. So if you just have a small trailer the bumper should be fine.

Bumpers used to be rated for more weight back before receiver hitches became common, but these days they are pretty much just for looks and to absorb the impact of an accident. I had a drop bumper on my old 85 F-250 that was rated for something like 10,000 lbs. I pulled a Bobcat around all the time with that thing. A guy rear ended me and totaled his Suburban, but it didn't do anything but take some dirt off my bumper.

Your best bet is to just get a receiver hitch. Definitely stronger than your bumper and it gives you many more options for towing different trailers. If you need a tow hook, just get one of those inserts with a hook on it.