Side-Channel VoIP Profiling Attack against Customer Service Automated Phone System

In many VoIP systems, Voice Activity Detection (VAD) is often used on VoIP traffic to suppress packets of silence in order to reduce the bandwidth consumption of phone calls. Unfortunately, although VoIP traffic is fully encrypted and secured, traffic analysis of this suppression can reveal identifying information about calls made to customer service automated phone systems. Because different customer service phone systems have distinct, but fixed (pre-recorded) automated voice messages sent to customers, VAD silence suppression used in VoIP will enable an eavesdropper to profile and identify these automated voice messages. In this paper, we will use a popular enterprise VoIP system (Cisco CallManager), running the default Session Initiation Protocol (SIP) protocol, to demonstrate that an attacker can reliably use the silence suppression to profile calls to such VoIP systems. Our real-world experiments demonstrate that this side-channel profiling attack can be used to accurately identify not only what customer service phone number a customer calls, but also what following options are subsequently chosen by the caller in the phone conversation.Comment: 6 pages, 12 figures. Published in IEEE Global Communications Conference (GLOBECOM), 202

The Impact of TLS on SIP Server Performance

This report studies the performance impact of using TLS as a transport protocol for SIP servers. We evaluate the cost of TLS experimentally using a testbed with OpenSIPS, OpenSSL, and Linux running on an Intel-based server. We analyze TLS costs using application, library, and kernel profiling, and use the profiles to illustrate when and how different costs are incurred, such as bulk data encryption, public key encryption, private key decryption, and MAC-based verification. We show that using TLS can reduce performance by up to a factor of 20 compared to the typical case of SIP over UDP. The primary factor in determining performance is whether and how TLS connection establishment is performed, due to the heavy costs of RSA operations used for session negotiation. This depends both on how the SIP proxy is deployed (e.g., as an inbound or outbound proxy) and what TLS options are used (e.g., mutual authentication, session reuse). The cost of symmetric key operations such as AES or 3DES, in contrast, tends to be small. Network operators deploying SIP over TLS should attempt to maximize the persistence of secure connections, and will need to assess the server resources required. To aid them, we provide a measurement-driven cost model for use in provisioning SIP servers using TLS. Our cost model predicts performance within 15 percent on average

A Study of Scams and Frauds using Social Engineering in “The Kathmandu Valley” of Nepal

Social Engineering scams are common in Nepal. Coupled with inability of government to enforce policies over technology giants and large swaths of population that are uneducated, social engineering scams and frauds are a real issue. The purpose of the thesis is to find out the extent and impact of social engineering attacks in “The Kathmandu valley” of Nepal. The Kathmandu valley consists of 3 cities including the capital city of Nepal. To conduct the research, the newspaper “The Kathmandu Post” from the year 2019 to 2022 was downloaded and searched for keywords “scam” and “fraud”. After which the results were manually examined to separate news reports of social engineering attacks in Nepal and other countries. Also, a survey was conducted by visiting parks in the Kathmandu valley. A total of 149 people were interviewed to collect data by asking 21 questions regarding social engineering attack faced by the interviewee. Further, literature review of the research papers published related to social engineering and phishing was conducted. The main finding of the thesis was that public awareness program are effective reducing the extent and impact of social engineering attacks in Nepal. The survey suggests large percentage of population have become victims of social engineering attack attempts. More than 70 percent have received messages on WhatsApp regarding fake lottery wins

A Comprehensive Survey of Voice over IP Security Research

We present a comprehensive survey of Voice over IP security academic research, using a set of 245 publications forming a closed cross-citation set. We classify these papers according to an extended version of the VoIP Security Alliance (VoIPSA) Threat Taxonomy. Our goal is to provide a roadmap for researchers seeking to understand existing capabilities and to identify gaps in addressing the numerous threats and vulnerabilities present in VoIP systems. We discuss the implications of our findings with respect to vulnerabilities reported in a variety of VoIP products. We identify two specific problem areas (denial of service, and service abuse) as requiring significant more attention from the research community. We also find that the overwhelming majority of the surveyed work takes a black box view of VoIP systems that avoids examining their internal structure and implementation. Such an approach may miss the mark in terms of addressing the main sources of vulnerabilities, i.e., implementation bugs and misconfigurations. Finally, we argue for further work on understanding cross-protocol and cross-mechanism vulnerabilities (emergent properties), which are the byproduct of a highly complex system-of-systems and an indication of the issues in future large-scale systems