Green-Fuzz: Efficient Fuzzing for Network Protocol Implementations

Recent techniques have significantly improved fuzzing, discovering many vulnerabilities in various software systems. However, certain types of systems, such as network protocols, are still challenging to fuzz. This article presents two enhancements that allow efficient fuzzing of network protocols. The first is Desock+, which simulates a network socket and supports different POSIX options to make Desock+ suitable for faster network protocol fuzzing. The second is Green-Fuzz, which sends input messages in one go and reduces the system-call overhead while fuzzing network protocols. We applied this modification to AFLNet, but it could be applied to any fuzzer for stateful systems. This is the maximum overhead we can avoid, when doing out-process fuzzing on stateful systems. Our evaluation shows that these enhancements make AFLNet up to four times faster.