Symbolic Execution in Practice: A Survey of Applications in Vulnerability, Malware, Firmware, and Protocol Analysis

Abstract: Symbolic execution is a powerful program analysis technique that allows for the systematic exploration of all program paths. Path explosion, where the number of states to track becomes unwieldy, is one of the biggest challenges hindering symbolic execution's practical application. To combat this, researchers have employed various strategies to enable symbolic execution on complex software systems. This paper introduces a systematic taxonomy of these strategies, categorizing them into two primary approaches: Scope Reduction, which aims to reduce the scope of symbolic execution to manageable portions of code, and Guidance Heuristics, which steer the symbolic execution engine toward promising paths. Using this taxonomy as a lens, we survey applications of symbolic executions in several domains such as vulnerability analysis, malware analysis, firmware re-hosting, and network protocol analysis. Finally, we identify promising directions for future research, including the application of symbolic execution to real-time operating systems and modern, type-safe languages.