I had an experience with along these lines from the other side recently, working with a student to write a plan for the research that he would be doing under me during a three-month visit. We had to be ultra-specific in order to meet visa requirements, but the project had a lot of uncertainties in it.
In fact, however, the challenge of writing a specific research statement was quite useful for making sure we thought a bit more in advance and were able to get a fast start once my student arrived.
I would recommend getting in touch with the person that you are expected be working with abroad, and set up a time to talk (Skype, Gchat, whatever) about some more specific goals. Some good examples of starting points for a discussion:
- Are there particular types of analysis technique that are likely to be used?
- Are there particular pieces of software that are likely to be good test cases?
- What is the goal? Do you want to find security issues, bugs, inefficiencies, usability, portability, robustness, something else? Or are you just trying to exercise the scalability of the techniques?
- What are some intermediate checkpoints that you can use to know if you are making progress towards your thesis? What should be done in 1 month? 3 months? 6 months?
It's OK if the answers change while you're there. Everybody understands that research is research and that things may change. But going in with a concrete plan will help a lot in making good use of your time, in understanding whether something has changed, and if so what you want to do about it.
And if the potential supervisor abroad can't make time for a meeting with you? Then maybe you should rethink whether this would be the right place to go...