A Stateful Web Service Firewall for BPEL

Today, the Business Process Execution Language (BPEL) is the most emerging specification for Web Service Composition, which is an important part of the SOA paradigm. Defining a stateful communication protocol, BPEL enables potential for new security vulnerabilities. In this paper, we present a severe Denial-of-Service attack on a leading BPEL engine, illustrating new threats on availability in the context of BPEL. Derived from our observations, we developed a protection concept and implemented an application level firewall fending these types of attacks.