RGFuzz: Rule-Guided Fuzzer for WebAssembly Runtimes
JunYoung Park, Yunho Kim, Insu Yun
IEEE Symposium on Security and Privacy 2025 · Day 1 · Web Security
In this insightful talk from IEEE S&P, JunYoung Park, Yunho Kim, and Insu Yun introduce **RGFuzz**, a novel **rule-guided fuzzer** specifically designed to uncover **semantic bugs** within **WebAssembly (Wasm) runtimes**. WebAssembly has rapidly emerged as a critical compilation target, lauded for its speed, safety, portability, and compact nature, making it ideal for porting applications to the web and beyond. To maximize performance, Wasm runtimes often employ **Just-In-Time (JIT) compilers** and sophisticated optimization techniques that translate Wasm bytecode into an **Intermediate Representation (IR)** before applying various compiler optimization rules. While these optimizations are crucial for speed, they introduce a significant attack surface: errors in these complex rules can lead to **miscompilations**, causing programs to execute incorrectly, or, in worst-case scenarios, introducing severe security vulnerabilities.