Is IP Multimedia Subsystem affected by ‘malformed message’ attacks? - An evaluation of OpenIMS

In this paper we assess the open IP Multimedia Subsystem (IMS) robustness against malformed message attacks. We employ an IMS test-bed architecture using two different testing suites; the PROTOS which is publicly available, and a proprietary one, that has been develop for the purpose of this specific work. Results have highlighted that although IMS can effectively handle well-known malformed messages, such as those utilized in PROTOS, it cannot manage satisfactorily unknown malformed messages. During the attack scenarios memory consumption increases up to 25%, while the end-to-end delay experienced by the users increases up to 4000%.