WARD: Efficient Memory Protection for WebAssembly on Tiny Embedded Systems

WebAssembly (Wasm) has recently gained attention in embedded systems due to its lightweight runtime support and broad compatibility with various languages and platforms. However, Wasm’s linear memory model lacks internal protection mechanisms, making it vulnerable to a wide range of memory safety violations. To address this, prior work has proposed techniques for protecting memory within the linear memory space. While effective to some extent, these approaches either suffer from limited detection coverage or are unsuitable for resource-constrained embedded systems. In this paper, we present WARD, a redzone-based memory protection technique tailored for Wasm in tiny embedded systems. At its core, WARD employs arandomized linear-to-physical address translation mechanism, which enables effective detection of memory violations without requiring specific hardware extensions. Our evaluation shows that WARD provides improved memory detection coverage over prior techniques, with reasonable performance of 24.2% on benchmark and 13.03% on real-world applications, and memory overhead suitable for embedded systems.