Hey all, Since I haven't really ever properly done it, i wanted to "officially" announce american fuzzy lop, a novel instrumentation-driven fuzzer that, among other things, had some luck finding a bunch of fairly interesting image parsing security issues (e.g., CVE-2013-6629, CVE-2013-6630). http://code.google.com/p/american-fuzzy-lop/ I have a blog post that discusses the design of the fuzzer in more detail: http://lcamtuf.blogspot.com/2014/08/a-bit-more-about-american-fuzzy-lop.html ...but in essence, the basic idea is to use high-performance instrumentation to get Markov-chain-style tuples that describe local state transitions within the program - (previous executed statement, current executed statement) - without paying any explicit attention to global control flow. This is used to automatically generate additional test cases from the initial file whenever novel state transitions are bumped into. The approach automatically produces a compact, ever-evolving corpus of interesting test cases to get good coverage of the tested program, well-suited for manual inspection or as a seed for other, more resource-intensive testing protocols. I think this works considerably better than coverage-only algorithms, but also avoids the complexity of instrumentation that tries to compare or reason about global execution paths. Cheers, /mz
