In Apache Synapse, by default no authentication is required for Java Remote Method Invocation (RMI). So Apache Synapse 3.0.1 or all previous releases (3.0.0, 2.1.0, 2.0.0, 1.2, 1.1.2, 1.1.1) allows remote code execution attacks that can be performed by injecting specially crafted serialized objects. And the presence of Apache Commons Collections 3.2.1 (commons-collections-3.2.1.jar) or previous versions in Synapse distribution makes this exploitable. To mitigate the issue, we need to limit RMI access to trusted users only. Further upgrading to 3.0.1 version will eliminate the risk of having said Commons Collection version. In Synapse 3.0.1, Commons Collection has been updated to 3.2.2 version.

Apache Axis2 before 1.5.2, as used in IBM WebSphere Application Server (WAS) 7.0 through 7.0.0.12, IBM Feature Pack for Web Services 6.1.0.9 through 6.1.0.32, IBM Feature Pack for Web 2.0 1.0.1.0, Apache Synapse, Apache ODE, Apache Tuscany, Apache Geronimo, and other products, does not properly reject DTDs in SOAP messages, which allows remote attackers to read arbitrary files, send HTTP requests to intranet servers, or cause a denial of service (CPU and memory consumption) via a crafted DTD, as demonstrated by an entity declaration in a request to the Synapse SimpleStockQuoteService.