CPU-based DoS attacks against SIP servers

Abstract

A key component of VoIP networks is the SIP signaling infrastructure. The reliance of public SIP servers on the Internet has opened up this critical infrastructure to a range of attacks. In particular, Denial of Service (DoS) attacks pose a serious security threat to the quality, reliability and availability of VoIP operations. In this paper, we investigate the impact of DoS attacks on SIP infrastructure, using a popular open source SIP server as a test bed. We have identi.ed four attack scenarios that can exploit vulnerabilities in existing SIP authentication protocols, and we demonstrate the practical impact of these attacks on the target server. In response to these vulnerabilities, we ha..