SIP Proxies: New Reflectors in the Internet

Abstract

Abstract. To mitigate identity theft in SIP networks, an inter-domain authentication mechanism based on certificates is proposed in RFC 4474 [10]. Unfortunately, the design of the certificate distribution in this mechanism yields some vulnerabilities. In this paper, we investigate an attack which exploits SIP infrastructures as reflectors to bring down a web server. Our experiments demonstrate that the attacks can be easily mounted. Finally, we discuss some potential methods to prevent this vulnerability.

Transaction-based authentication and key agreement protocol for inter-domain VoIP

“…This protocol offers no confidentiality protection for conveying a session key and, as for S/MIME, requires that network intermediaries do not alter the message content. It is also subject to DoS attacks because of signature processing and certificate recovering by the responder, as explained in [57].…”