VoIP vulnerabilities are weaknesses in the VoIP protocol or its implementations that expose users to privacy violations and other problems. VoIP is a group of technologies that enable voice calls online. VoIP contains similar vulnerabilities to those of other internet use.
Risks are not usually mentioned to potential customers.[1] VoIP provides no specific protections against fraud and illicit practices.
Unencrypted connections are vulnerable to security breaches. Hackers/trackers can eavesdrop on conversations and extract valuable data.[2] [3]
Attacks on the user network or internet provider can disrupt or destroy the connection. Since VoIP requires an internet connection, direct attacks on the internet connection, or provider, can be effective. Such attacks target office telephony. Mobile applications that do not rely on an internet connection to make calls[4] are immune to such attacks.
VoIP phones are smart devices that need to be configured. In some cases, Chinese manufacturers are using default passwords that lead to vulnerabilities.[5]
While VoIP is relatively secure, it still needs a source of internet, which is often a Wi-Fi network, making VoIP subject to Wi-Fi vulnerabilities[6]
VoIP is subject to spam called SPIT (Spam over Internet Telephony). Using the extensions provided by VoIP PBX capabilities, the spammer can harass their target from different numbers. The process can be automated and can fill the target's voice mail with notifications. The spammer can make calls often enough to block the target from getting important calls.[7]
VoIP users can change their Caller ID (a.k.a. Caller ID spoofing), allowing a caller to pose as a relative or colleague in order to extract information, money or benefits from the target.[8]