Explore how Firefox utilizes WebAssembly to protect itself from exploitable libraries in this 30-minute conference talk. Learn about the innovative approach to mitigating memory safety vulnerabilities in third-party C libraries, a major source of zero-day attacks in modern applications. Discover the journey of migrating Firefox to an architecture where these libraries run in lightweight in-memory sandboxes powered by WebAssembly, a feature that has been in production since 2020. Delve into the challenges faced during implementation and understand RLBox, the language-level framework developed to address these issues. Gain insights into real-world applications of RLBox in Firefox, examine the performance impact of sandboxing, and find out how to apply these tools to your own projects for enhanced security.