Red Hat Security Advisory 2015-2548-01 – Red Hat JBoss Web Server is a fully integrated and certified set of components for hosting Java web applications. The Apache Commons Collections library provides new interfaces, implementations, and utilities to extend the features of the Java Collections Framework. It was found that the Apache commons-collections library permitted code execution when deserializing objects involving a specially constructed chain of classes. A remote attacker could use this flaw to execute arbitrary code with the permissions of the application using the commons-collections library.