



© 2007 IBS Communications Limited



While Spit is certainly a technical possibility, to date, we have not seen a lot of it. In 2004, the peer to peer VoIP network Skype got hacked into, and users were inundated with unsolicited audio messages. Shortly thereafter, Skype had found and closed the loophole in the network. One other legal recourse is to get on the national Do Not Call list, to prevent solicitors from bombarding your voice mail box
Eavesdropping
Probably one of the scariest vulnerabilities of VoIP is the ability of an outsider to eavesdrop on a private conversation. This concept is nothing new to IP data networks, and generally requires a packet analyzer to intercept IP packets, and in the case of VoIP, saving the data as an audio file. Hackers then have the ability to learn user ids and passwords, or worse, to gain knowledge of confidential business information.
While it is true that eavesdropping occurs on traditional telephone lines as well as cellular networks, for someone to tap into your home phone line pretty much requires a physical presence outside your house. In the case of an IP network, a hacker requires only a laptop, some readily available software, and the knowledge of how to hack into your network.
Security analysts have long used encryption techniques to protect the confidentiality of data traveling through an IP network, and the same concept holds true for voice packets. The challenge with voice is to encrypt strongly and quickly, to protect confidentiality and as not to slow down the packet flow.
Nevertheless, if someone really wants to listen in on your calls, no type of telecommunication is 100% secure.
Phishing the Waters of Voice over IP
Another variation of an email attack, Phishing is designed to trick a user into revealing sensitive data such as user names, passwords, bank accounts, credit cards, and even social security numbers. In the case of VoIP, the attack could come as a voice mail message urging you to call a designated number and provide your user information. Even if the call is automated, touch tones can be easily deciphered. Depending on what information they get, hackers can use it to access bank accounts, or to steal identities.
While you can program a PBX to restrict call backs to known phishers, as more users become familiar with the pitfalls of the Internet, it becomes common knowledge to never give out sensitive information to automated media, be it via data or voice.
SIP Registration Hijacking
The Session Initiation Protocol (SIP) is becoming widely accepted as the method for setting up VoIP phone calls. The process involves a Registrar (in some cases the company PBX itself), which maintains a database of all users subscribed to the network, and basically maps their telephone number to an IP address.
Registration hijacking occurs when the packet header of either party is intercepted by a hacker, who substitutes his IP address for that of the legitimate one. Attacks can take the form of fraudulent toll free calls, denial of service attacks that can render the users device useless, or a simple diversion of communication.
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