Scala is an open-source programming language created by Martin Odersky in 2001 and released under the BSD or Berkeley Software Distribution license. The language consolidates object-oriented and functional programming in one high-level and robust language. Scala also maintains static types that help to reduce tricky errors in real-world software systems.

In this paper, we introduce the first Scala-specific security analysis too that works based on a concolic based fuzzing for evaluating large-scale codes written in Scala, we call our tool Kaizen. To evaluated our approach, we have analyzed 1,000 real-world projects and core libraries written in Scala existing on GitHub. As a result, our testing system could report 101 vulnerabilities some of those were unknown before. Furthermore, the outcome of our performance analysis on ScalaBench illustrates 49% runtime overhead that proves the efficiently of Kaizen in comparison with related tools in the JVM ecosystem.