This presentation describes the summary of VoIP infrastructure and related vulnerabilities and security concerns.

1. VoIP(Voice over IP) Security
Dayanand Prabhakar

2. Project scope
• Understanding VoIP
• Threat profiling of VoIP application
• Develop the test case and
Methodologies to test VoIP application
• Sample testing of one VoIP application
and report presentation
• Mitigation strategies
• Conclusion

3. What is VoIP?
 Routingof voice conversations over the
Internet or through any other IP-based
network.

4. Benefits
 VoIP enables convergence of data,
voice, and video onto single network.
 Attractive opportunities
– Reducing costs
– Reducing complexities
– Enabling progressive business gains

5. VoIP implementations
 Business-grade VoIP telephony
– Designed specifically for business grade usage
 Softphones
– X-lite, 3cx , Express Talk
 Instant Messaging voice services
– Application such as AIM, MSN, Apple iChat offer ‘voice chat’
functionality
 Mobile VoIP
– Requires mobile telephone with 3G or wireless connectivity
– Using a mobile version of a Softphone mobile devices and
telephones are capable of offering VoIP services
 VoIP handsets
– Requires a VoIP handset from the service provider
– Offer call functionality and services similar of typical PSTN
services

6. Protocols
 Signaling Protocol
– Create, modify, and terminate sessions
with participants
– Conferences
– Proxies
– Authentication
 Transport /Carrier Protocol
– Manages the actual voice data

7. Protocols
 Session Initiation Protocol (SIP)
– Signaling protocol
– Session Initiation Protocol
– Application layer control protocol for
initiating VOIP sessions
– Currently most favored protocol for new
systems

8. Protocols
 H.323
– One of the earliest sets of VoIP standards
by ITU-T
– Handles voice, video and data conferencing
– Some limitations, but most VoIP traffic
utilizes this today
 Real-time Transport Protocol (RTP)
– Used for media transfer by other protocols
– Fast, scalable and efficient
– RTP uses UDP

9. Most Common VOIP Security
Mistakes
1. Treating VOIP security the same way as Network
security
2. Not treating VOIP security the same way as Network
security
How it’s the Same How it’s Different
• Uses mostly the same • Some unique protocols
protocols • Traditional Security devices
• Uses mostly the same (Firewalls can disrupt service)
Operating Systems • People treat it like the old phone
• Many of the same system
threats

10. Complexities in VOIP
Architecture

11. Voice over IP Threats
Threats are categorized into following
parameters.
 Threats against availability
 Threats against confidentiality
 Threats against integrity
 Threats against social context

12. Voice over IP Threats
Against Availability Against Confidentiality
 Call flooding  Eavesdropping
 Toll Fraud  Call pattern Tracking
 Call hijacking  Reconstruction
 Fuzzing
 TDOS

13. Voice over IP Threats
Against Integrity Against Social context
 Message
 Misrepresentation
Alteration  Call SPIT (Spam over
 Call Rerouting Internet Telephony )
 Media Alteration
 Vising

14. What are the Threat Vectors?
 OS Exploits
 Signaling Attacks
 Endpoint Admin Privilege Exploits
 Real Time Protocol (RTP) Attacks
 DoS Attacks
 IP PBX &Telephony Server Exploits

15. Specialized Hacking Tools
 BackTrack Penetration Testing Distribution
– www.backtrack-linux.org/
 Wireshark (http://www.wireshark.org)
– Packet Sniffer
 Cain and Abel (http://www.oxid.it)
– Password cracker
– ARP spoofing
– RTP Playback
 SiVuS (http://www.vopsecurity.org/html/tools.html)
– VoIP Vulnerability Scanner
– General Purpose VoIP packet generation, spoofing,
testing tool.

16. Attack on VoIP

18. Mitigation Strategies
 Create VOIP Specific Security Policies
 Segmentation as appropriate
– Utilize separate VLANs for voice and data
 Device Hardening
– Do not use default passwords
– Turn off unnecessary services
– Apply vendor supplied patches in a timely manner
– Perform vendor installation security checklist to harden
applications
 Pay attention to Security Risk Assessments and
planning against the VOIP infrastructure

19. Key Mitigation Strategies
 Apply Encryption where possible
 Use tools to test the network
 Utilize VoIP aware Firewalls, Intrusion Prevention Systems
 Continue to protect against traditional system attacks (Toll
Fraud, Modem Security, Social Networking Attacks & etc.)
 Avoid Single point of failure

20. Conclusion
 VoIP is established as the future of
telephones
 Security is critical when designing,
implementing and maintaining VoIP
systems
 VoIP technology should there by provide a
balance between security and business
needs .

21. References
 VOIPSA
– http://www.voipsa.org/
 The VOIP Dilemma SANS Institute
– http://www.sans.org/rr/whitepapers/voip/1452.php
 NIST - Security Considerations for Voice Over IP
Systems,
– http://csrc.nist.gov/publications/nistpubs/800-
58/SP800-58-final.pdf
 IP Telephony & VoIP: Security technical
implementation guide
– http://csrc.nist.gov/pcig/STIGs/VoIP-STIG-V2R2.pdf

22. THANK YOU
Dayanand Prabhakar