Buffer overflows are the source of a vast majority of vulnerabilities in today's software. Existing solution for detecting buffer overflow, either statically or dynamically, have serious drawbacks that hinder their wider adoption by practitioners. In this paper we present an automated overflow detection technique based on model checking and iterative refinement. We discuss advantages, and limitations, of our approach with respect to today's existing solutions. We also describe how our approach may be implemented on top of a model checking technology being developed at the Software Engineering Institute (SEI).