Consider using more modern data structures as a way of avoiding buffer overflows. Reading into a std::string won't overflow, and std::vectors are much safer than arrays. I don't know what your application is, and it's possible that raw buffers are used because you need the speed, but it's more common that they are used because that's what the original programmers were comfortable with.
Searching for memory leaks with the tools mentioned is a good idea, but they may not find all potential leaks, while using standard strings and container classes can eliminate problems you didn't realize you had.
