1. The study and demonstration on SIP security vulnerabilities
Mahidhar Penigi
Vamsi Krishna Karnati

2. Introduction Session Initiation Protocol, is a text based protocol
Signaling protocol to initiate, manage and terminate voice sessions
BICC, H.323, MGCP and MEGACO
SIP is very similar to HTTP
For secure SIP transmissions SIP secure (SIPS) is used
SIP establishes and terminates a session in a series of handshakes (Illustrated in the next slide)

3. The three way handshake

4. Major drawbacks of SIP
SIP does not have inbuilt security Elements like:
Encryption Authentication, and Confidentiality have to deployed a another layer for additional security in SIP
Encryption: Malicious users and hackers are easily able to intercept and decode SIP messages retrieved using the simple networking tools/softwares.
Authentication:
It is not very simple for an unauthorized user to be traced down without additional layers of security.
Due to this IP spoofing could be performed to enter the network and by replacing another device with the same IP and kicking it out of the network.
This user is then authenticated within the SIP network since authentication schemes come as a part of an external solution and is not inbuilt

5. SIP message protection is also required
Protecting content exchanged between two user or end devices during any kind of exchange over an IP network is called message protection
Very important for end to end voice delivery to be reliable and secure to avoid a major section of attacks that are classified by the attacker being able to recognize and understand an ongoing target session

6. Attacks due to lack of encryption
Malformed message attacks
Message Tampering

7. Attacks due to lack of authentication
Denial of service attacks
IP spoofing
IP address of an authenticated device is borrowed temporarily to utilize the services of the network, this is not authorized
Computer.howstuffworks.com

8. Attacks due to lack of authentication
Man in middle attacks, Eavesdropping and Registration Hacking

9. Other Attacks
Proxy Impersonation is where the attacker claims the identity of the proxy server taking temporary control over all ongoing sessions (voice) and devices interacting with it

10. The solution for better security
A Telephony Solution that is need based is often deployed over SIP to take care of the general security issues mentioned earlier
TCP/IP rather than UDP for SIP
Even though most SIP deployments are a compromise in infrastructure when additional security is required
SIP is going to be accompanied with some kind of a TLS as well
Raw UDP transport method with ZRTP could also keep most hackers and attacks away

11. PACKET TRACER 5 Network simulation Program provided by CISCO.
It helps to learn complex Technology concepts.
Unlimited Devices can be added into a network for demonstration.
Cisco certified tool for learning complex networks.

12. Demonstration of Attacks: Packet Tracer 5.0
IP spoofing
Registration Hacking
Denial of Service due to Packet flooding

13. Conclusion
Now specially with the advent of VoLTE, that provisions for a higher level integration between the PSTN, IMS and VoIP networks is higher, and a small loophole in one segment of one of the voice based networks could eventually lead to a bigger threat for the larger VoLTE system in place. SIP is one such loophole and it is very necessary to recognize, understand and prevent the issues pertaining to Session Initiation Protocol (SIP) and hence deploy a better network with better security standards.

14. References www.voip-info.org/wiki/view/SIP+security
download.securelogix.com/library/SIP_Security pdf