Security for the signaling plane of the SIP protocol

VOIP protocols are gaining greater acceptance amongst both users and service providers. This thesis will aim to examine aspects related to the security of signaling plane of the SIP protocol, one of the most widely used VOIP protocols. Firstly, I will analyze the critical issues related to SIP, then move on to discuss both current and possible future solutions, and finally an assessment of the impact on the performance of HTTP digest authentication, IPsec and TLS, the three main methods use

Security aspects in voice over IP systems

Security has become a major concern with the rapid growth of interest in the internet. This project deals with the security aspects of VoIP systems. Various supporting protocols and technologies are considered to provide solutions to the security problems. This project stresses on the underlying VoIP protocols like Session Initiation Protocol (SIP), Secure Real-time Transport Procotol (SRTP), H.323 and Media Gateway Control Protocol (MGCP). The project further discusses the Network Address Translation (NAT) devices and firewalls that perform NAT. A firewall provides a point of defense between two networks. This project considers issues regarding the firewalls and the problems faced in using firewalls for VoIP; it further discusses the solutions about how firewalls can be used in a more secured way and how they provide security

Secure high definition video conferencing

The aim of this review is to study technologies involved in a video conference through Internet. Some security issues and solutions to them are also covered in this report. At first, several video conference environments are presented to clarify concepts. Also some commercial solutions are mentioned. Secondly, signalling protocols, specially SIP, are studied to be used in the set up of a video conference. Possibilities to secure SIP are also covered in the theoretical study. Thirdly, the Secure RTP protocol is presented to be used to protect the media flows. Then a key agreement mechanism, MIKEY, is stated to make the key agreement needed to establish a crypto session for SRTP. After the background study, an implementation of a secure video conferencing platform using miniSIP and RTP Packet Reflector is proposed. Then, the final implementation is detailed, showing up the problems appeared during this process and possible solutions to them. Possible new features for the system are also proposed. Finally, some measurement results taken using the new software are presented and analyzed

SIP based IP-telephony network security analysis

Masteroppgave i informasjons- og kommunikasjonsteknologi 2004 - Høgskolen i Agder, GrimstadThis thesis evaluates the SIP Protocol implementation used in the Voice over IP (VoIP) solution at the fibre/DSL network of Èlla Kommunikasjon AS. The evaluation focuses on security in the telephony service, and is performed from the perspective of an attacker trying to find weaknesses in the network. For each type of attempt by the malicious attacker, we examined the security level and possible solutions to flaws in the system. The conclusion of this analysis is that the VoIP service is exploitable, and that serious improvements are needed to achieve a satisfying level of security for the system

Protection of VoIP networks and their testing

Hlavným dôvodom pre vytvorenie tejto diplomovej práce je existencia čoraz väčšieho množstva potenciálnych hrozieb pre hlasové siete VoIP pracujúce na IP protokole. Táto práca sa venuje testovaniu rôznych druhov útokov a zároveň poskytuje možnosti riešenia obrany proti týmto nežiaducim skutočnostiam. V práci je poukázané na rôzne typy aktuálnych útokov proti nezabezpečeným alebo len veľmi málo zabezpečeným štruktúram. Teoretická časť je venovaná analýze a opisu širokého spektra VoIP protokolov od signalizačných (SIP, IAX2), cez transportné (TCP, UDP, RTP, RTCP) až po protokoly, ktoré slúžia ako bezpečnostné mechanizmy (SRTP, ZRTP, IPsec, SDES). Ďalej je pozornosť venovaná riešeniu pomocou softvérovej ústredne Asterisk ako jedného z možných a často nasadzovaných riešení IP softvérových pobočkových ústrední typu open source a je poukázané na možnosti útokov proti takémuto systému, práve z toho dôvodu, že otvorené systémy sú náchylnejšie k rôznym typom útokov, pretože vyžadujú pokročilú správu a neustále sledovanie nových trendov v oblasti bezpečnosti. Posledný blok teoretickej časti je venovaný všeobecným hrozbám a typom útokov proti sieťam VoIP. Praktická časť sa zaoberá návrhom a vytvorením webovej aplikácie s názvom ,,VoIP Hacks using PHP“ v jazyku PHP, ktorá má za úlohu vykonávať tri základné druhy útokov a to: odpočúvanie, ukončenie hovoru a záplava volaním. Ako doplnok k týmto útokom je pridaná možnosť skenovania portov zvolenej siete. Aplikáciu je možné ovládať pohodlne cez užívateľské rozhranie webového prehliadača, pričom všetky výsledky zachytených útokov je možné zobraziť priamo v prehliadači. Testovanie chodu aplikácie prebehlo v prostredí prehliadačov Google Chrome a Mozzila Firefox. V tomto webovom nástroji je kladený dôraz na spoluprácu s linuxovými terminálovými programami Tshark, BYE Teardown, INVITE flooder či Nmap, ktoré jednotlivé útoky generované z webového rozhrania priamo vykonávajú a vracajú požadované výstupné hodnoty.Main goal of creating this diploma thesis is existence of increasingly amount of potential threats against IP voice networks (VoIP). The thesis is devoted to testing of various types of attacks and provides some possible solutions for this systems as well. The work points out to a various types of current attacks against either insecure or very little secure structures. The theoretical part is dedicated to analyse and description of wide spectrum of VoIP protocols including signaling protocols (SIP, IAX2), transport protocols (RTP, RTCP) and security protocols (SRTP, ZRTP, IPsec, SDES). Further attention is dedicated to the one of possible open source IP PBX solutions called Asterisk. There is shown a variety of possible attacks against this system due to its openness, because open systems always tend to be more susceptible for various attacks as they need an advanced administration and endless need for searching of new trends in area of security. The last block of the theoretical part is focused on common threats and types of attacks against VoIP networks. The practical part is about design and creation of web application called ,,VoIP Hacks using PHP” written in PHP scripting language and ist main task is to execute three basic attacks: eavesdropping, call drop and call flood. There is also a possibility of port scanning of selected network which is added as supplementary part of this application. The application can be comfortably managed from web browser user interface. All captured data can be displayed directly into the web browser. Tests of the application were performed on Google Chrome and Mozzila Firefox browsers. There is an accent placed on cooperation between the application and terminal linux programmes such as Tshark, BYE Teardown, INVITE flooder or Nmap, which all accept commands from web interface and interpret gained output values back to the web browser.

Estudio de la movilidad en redes de siguiente generación

El continuo avance de las redes de telecomunicaciones nos proporciona cada vez más facilidades en todos los ámbitos de nuestra vida. En este caso, nos hemos centrado en el estudio de la movilidad en Redes de Siguiente Generación. Una parte del presente proyecto se ha realizado en colaboración con Deutsche Telekom AG, durante una estancia de seis meses trabajando como colaboradora en sus laboratorios con emplazamiento en Berlín. El principal objetivo de este proyecto ha sido realizar un estudio sobre los diferentes estándares y tecnologías que facilitan la movilidad en Redes de Siguiente Generación. Por ello, en la primera parte se han estudiado los diferentes grupos de trabajo centrados en este aspecto, así como se ha recabado información sobre productos y soluciones disponibles en el mercado, para obtener una visión global de la situación actual. Como se puede comprobar más adelante, esta primera parte es la más extensa de todo el documento. Esto se debe a que es, probablemente, la parte más importante del trabajo, ya que contiene el estudio de los mecanismos que más tarde nos servirán para dar una solución teórica a los distintos escenarios que se plantean. En la segunda parte del proyecto, nos hemos centrado en desarrollar varios escenarios de interés en sistemas de Redes de Siguiente Generación y aportar, de forma posterior, posibles soluciones teóricas. Para finalizar, se han expuesto las conclusiones extraídas como resultado del trabajo y los aspectos que se podrán tratar sobre el mismo en un futuro próximo.Ingeniería de Telecomunicació

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

Secure Service Provisioning (SSP) Framework for IP Multimedia Subsystem (IMS)

Mit dem Erscheinen mobiler Multimediadienste, wie z. B. Unified Messaging, Click-to-Dial-Applikationen, netzwerkübergeifende Multimedia-Konferenzen und nahtlose Multimedia-Streming-Dienste, begann die Konvergenz von mobilen Kommunikationsetzen und Festnetzen, begleitet von der Integration von Sprach- und Datenkommunikations-Übertragungstechnik Diese Entwicklungen bilden die Voraussetzung für die Verschmelzung des modernen Internet auf der einen Seite mit der Telekommunikation im klassischen Sinne auf der anderen. Das IP Multimedia-Subsystem (IMS) darf hierbei als die entscheidende Next-Generation-Service-Delivery-Plattform in einer vereinheitlichten Kommunikationswelt angesehen werden. Seine Architektur basiert auf einem modularen Design mit offenen Schnittstellen und bietet dedizierte Voraussetzungen zur Unterstützung von Multimedia-Diensten auf der Grundlage der Internet-Protokolle. Einhergehend mit dieser aufkommenden offenen Technologie stellen sich neue Sicherheits-Herausforderungen in einer vielschichtigen Kommunikationsinfrastruktur, im Wesentlichen bestehend aus dem Internet Protokoll (IP), dem SIP-Protokoll (Session Initiation Protocol) und dem Real-time Transport Protokoll (RTP). Die Zielsetzung des Secure Service Provisioning-Systems (SSP) ist, mögliche Angriffsszenarien und Sicherheitslücken in Verbindung mit dem IP Multimedia Subsystem zu erforschen und Sicherheitslösungen, wie sie von IETF, 3GPP und TISPAN vorgeschlagen werden, zu evaluieren. Im Rahmen dieser Forschungsarbeit werden die Lösungen als Teil des SSP-Systems berücksichtigt, mit dem Ziel, dem IMS und der Next-Generation-SDP einen hinreichenden Schutz zu garantieren. Dieser Teil, der als Sicherheitsschutzstufe 1 bezeichnet wird, beinhaltet unter anderem Maßnahmen zur Nutzer- und Netzwerk-Authentifizierung, die Autorisierung der Nutzung von Multimediadiensten und Vorkehrungen zur Gewährleistung der Geheimhaltung und Integrität von Daten im Zusammenhang mit dem Schutz vor Lauschangriffen, Session-Hijacking- und Man-in-the-Middle-Angriffen. Im nächsten Schritt werden die Beschränkungen untersucht, die für die Sicherheitsschutzstufe 1 charakteristisch sind und Maßnahmen zu Verbesserung des Sicherheitsschutzes entwickelt. Die entsprechenden Erweiterungen der Sicherheitsschutzstufe 1 führen zu einem Intrusion Detection and Prevention-System (IDP), das Schutz vor Denial-of-Service- (DoS) / Distributed-Denial-of-Service (DDoS)-Angriffen, missbräuchlicher Nutzung und Täuschungsversuchen in IMS-basierten Netzwerken bietet. Weder 3GPP noch TISPAN haben bisher Lösungen für diesen Bereich spezifiziert. In diesem Zusammenhang können die beschriebenen Forschungs- und Entwicklungsarbeiten einen Beitrag zur Standardisierung von Lösungen zum Schutz vor DoS- und DDoS-Angriffen in IMS-Netzwerken leisten. Der hier beschriebene Ansatz basiert auf der Entwicklung eines (stateful / stateless) Systems zur Erkennung und Verhinderung von Einbruchsversuchen (Intrusion Detection and Prevention System). Aus Entwicklungssicht wurde das IDP in zwei Module aufgeteilt: Das erste Modul beinhaltet die Basisfunktionen des IDP, die sich auf Flooding-Angriffe auf das IMS und ihre Kompensation richten. Ihr Ziel ist es, das IMS-Core-Netzwerk und die IMS-Ressourcen vor DoS- und DDoS-Angriffen zu schützen. Das entsprechende Modul basiert auf einer Online Stateless-Detection-Methodologie und wird aktiv, sobald die CPU-Auslastung der P-CSCF (Proxy-Call State Control Function) einen vordefinierten Grenzwert erreicht oder überschreitet. Das zweite Modul (IDP-AS) hat die Aufgabe, Angriffe, die sich gegen IMS Application Server (AS) richten abzufangen. Hierbei konzentrieren sich die Maßnahmen auf den Schutz des ISC-Interfaces zwischen IMS Core und Application Servern. Das betreffende Modul realisiert eine Stateful Detection Methodologie zur Erkennung missbräuchlicher Nutzungsaktivitäten. Während der Nutzer mit dem Application Server kommuniziert, werden dabei nutzerspezifische Zustandsdaten aufgezeichnet, die zur Prüfung der Legitimität herangezogen werden. Das IDP-AS prüft alle eingehenden Requests und alle abgehenden Responses, die von IMS Application Servern stammen oder die an IMS Application Server gerichtet sind, auf ihre Zulässigkeit im Hinblick auf die definierten Attack Rules. Mit Hilfe der Kriterien Fehlerfreiheit und Processing Delay bei der Identifikation potenzieller Angriffe wird die Leistungsfähigkeit der IDP-Module bewertet. Für die entsprechenden Referenzwerte werden hierbei die Zustände Nomallast und Überlast verglichen. Falls die Leistungsfähigkeit des IDP nicht unter den Erwartungen zurückbleibt, wird ein IDP-Prototyp zur Evaluation im Open IMS Playground des Fokus Fraunhofer 3Gb-Testbeds eingesetzt, um unter realen Einsatzbedingungen z. B. in VoIP-, Videokonferenz- , IPTV-, Presence- und Push-to-Talk-Szenarien getestet werden zu können.With the emergence of mobile multimedia services, such as unified messaging, click to dial, cross network multiparty conferencing and seamless multimedia streaming services, the fixed–mobile convergence and voice–data integration has started, leading to an overall Internet–Telecommunications merger. The IP Multimedia Subsystem (IMS) is considered as the next generation service delivery platform in the converged communication world. It consists of modular design with open interfaces and enables the flexibility for providing multimedia services over IP technology. In parallel this open based emerging technology has security challenges from multiple communication platforms and protocols like IP, Session Initiation Protocol (SIP) and Real-time Transport Protocol (RTP). The objective of Secure Service Provisioning (SSP) Framework is to cram the potential attacks and security threats to IP Multimedia Subsystem (IMS) and to explore security solutions developed by IETF, 3GPP and TISPAN. This research work incorporates these solutions into SSP Framework to secure IMS and next generation Service Delivery Platform (SDP). We define this part as level 1 security protection which includes user and network authentication, authorization to access multimedia services, providing confidentiality and integrity protection etc. against eavesdropping, session hijacking and man-in-the middle attacks etc. In the next step, we have investigated the limitations and improvements to level 1 security and proposed the enhancement and extension as level 2 security by developing Intrusion Detection and Prevention (IDP) system against Denial-of-Service (DoS)/Distributed DoS (DDoS) flooding attacks, misuses and frauds in IMS-based networks. These security threats recently have been identified by 3GPP and TISPAN but no solution is recommended and developed. Therefore our solution may be considered as recommendation in future. Our approach based on developing both stateless and stateful intrusion detection and prevention system. From development point of view, we have divided the work into two modules: the first module is IDP-Core; addressing and mitigating the flooding attacks in IMS core. Its objective is to protect the IMS resources and IMS-core entities from DoS/DDoS flooding attacks. This module based on online stateless detection methodology and activates when CPU processing load of P-CSCF (Proxy-Call State Control Function) reaches or crosses the defined threshold limit. The second module is IDP-AS; addressing and mitigating the misuse attacks facing to IMS Application Servers (AS). Its focus is to secure the ISC interface between IMS Core and Application Servers. This module is based on stateful misuse detection methodology by creating and comparing user state (partner) when he/she is communicating with application server to check whether user is performing legitimate or illegitimate action with attacks rules. The IDP-AS also compared the incoming request and outgoing response to and from IMS Application Servers with the defined attacks rules. In the performance analysis, the processing delay and attacks detection accuracy of both Intrusion Detection and Prevention (IDP) modules have been measured at Fraunhofer FOKUS IMS Testbed which is developed for research purpose. The performance evaluation based on normal and overload conditions scenarios. The results showed that the processing delay introduced by both IDP modules satisfied the standard requirements and did not cause retransmission of SIP REGISTER and INVITE requests. The developed prototype is under testing phase at Fraunhofer FOKUS 3Gb Testbed for evaluation in real world communication scenarios like VoIP, video conferencing, IPTV, presence, push-to-talk etc

Securing media streams in an Asterisk-based environment and evaluating the resulting performance cost

When adding Confidentiality, Integrity and Availability (CIA) to a multi-user VoIP (Voice over IP) system, performance and quality are at risk. The aim of this study is twofold. Firstly, it describes current methods suitable to secure voice streams within a VoIP system and make them available in an Asterisk-based VoIP environment. (Asterisk is a well established, open-source, TDM/VoIP PBX.) Secondly, this study evaluates the performance cost incurred after implementing each security method within the Asterisk-based system, using a special testbed suite, named DRAPA, which was developed expressly for this study. The three security methods implemented and studied were IPSec (Internet Protocol Security), SRTP (Secure Real-time Transport Protocol), and SIAX2 (Secure Inter-Asterisk eXchange 2 protocol). From the experiments, it was found that bandwidth and CPU usage were significantly affected by the addition of CIA. In ranking the three security methods in terms of these two resources, it was found that SRTP incurs the least bandwidth overhead, followed by SIAX2 and then IPSec. Where CPU utilisation is concerned, it was found that SIAX2 incurs the least overhead, followed by IPSec, and then SRTP

Segurança em VoIP: ameaças aos sistemas VoIP

Voice communication over IP networks, known as VoIP, is being increasingly adopted. With this growth new businesses new products, suppliers and also new types of network attacks. As any application, VoIP is also very vulnerable to these threats. This work enumerates these threats and establishes recommendations to minimize VoIP vulnerability.A comunicação de voz sobre redes IP, conhecida como VoIP, vem crescendo muito. E com esse crescimento surgem novos negócios, novos produtos, fornecedores e também novos tipos de ataque. Como toda aplicação, VoIP se torna também vulnerável a ataques no mundo IP. O objetivo deste trabalho é identificar essas ameaças e estabelecer recomendações para diminuir a vulnerabilidade do VoIP