Abstract
When source code is unavailable, patching security vulnerabilities in binaries requires scarce reverse engineering expertise and specialized tooling. We present Dilipa, a binary micro-patching system that enables users to specify patches as edits to lifted C code. Dilipa operates on an AST-based intermediate representation enriched with provenance metadata linking high-level constructs to underlying binary instructions, registers, and memory locations. A frontend compares the original and edited ASTs to extract minimal patch descriptions, and a backend applies them to the binary via direct instruction replacement or trampolines. By focusing on micro-patches, small and localized modifications, our approach keeps binary changes minimal and enables post-patch validation through relational binary analysis, providing evidence that no unintended semantic changes have been introduced. We demonstrate Dilipa on three case studies involving real embedded systems, including input validation, buffer overflow, and race condition bugs.