Unauthenticated RCE in H2 Database Console. This issue has the same root cause as the infamous Log4Shell vulnerability in Apache Log4j (JNDI remote class loading). H2 is a very popular open-source Java SQL database offering a lightweight in-memory solution that doesn’t require data to be stored on disk. This makes it a popular data storage solution for various projects from web platforms like Spring Boot to IoT platforms like ThingWorks. The com.h2database:h2 package is part of the top 50 most popular Maven packages, with almost 7000 artifact dependencies.