This is a collection of miscellaneous bomb defusing challenges. Defusing each bomb requires reverse-engineering a binary to supply the correct input.
A great introduction to binary reversing, it's a series of 6 levels written by a professor at Carnegie Mellon. I'd recommend brushing up on your assembly and GDB.
Four well-written challenges which quickly ramp up in difficulty. For the most part, they only require knowledge of assembly to solve. Python skills and a very basic understanding of memory corruption will also be helpful.