Megha Verma

9 VoIP Security Threats and How to Fix Them

VoIP, Voice over Internet protocol, is the future of business communications. Thanks to its versatility, flexibility, and affordability, it is becoming an important part of the business telephony system. VoIP telephony is a clearer, faster, and more comprehensive communication medium for industries of all sizes to run business over the phone, but is it secure?

Considering the rising number of cybercrime around the world, the importance of security has become paramount. Phishing attacks, scam calls, malware, and other unknown security threats have put the business in disastrous situations.

Industries are losing their confidential information and money at alarming rates due to the loopholes, which can be closed with security alternatives.

Importance of VoIP Security:

Data breaches are affecting millions of businesses around the world. Approximately 3.5 billion people saw their personal data stolen, and around 62% of businesses become victims of phone scams, hijacking their personal information on the phone.

As VoIP relies on the Internet to communicate, this makes it more vulnerable to cyber-attacks.

According to Kaspersky Security Network, approximately 25% of Wi-Fi networks around the world don't use any encryption, so a VoIP provider, who is not focusing on security, can be a serious threat to your business.

Most Common VoIP Threats and How to Fix Them:

1. Security Threats:

Security threats are one of the most common types of VOIP threats. You will be surprised to know that a simple lapse in the network may lead to huge effects on the quality and security of VoIP networks.

These assessments should only be performed by independent and verified agencies so that the chances of having a problem become minimum.

Some of the common areas that need expert assessment are:

* Firewall configuration: Your firewall has to be kept away from cybercriminals.

* Gateway assessments: VoIP is transferred to the public network by VoIP gateways; therefore, the protection mechanism should be in place on your network.

* Cyberattack simulations: This will help you access all the vulnerabilities and prevent intrusions.

* Patching procedures: It should be accessed to identify if the software/hardware has a weakness that needs to be addressed.

How to fix: Keep accessing the network and hire experts to clear all VoIP security blind spots.

2. Network Firewalls:

Firewalls are designed to give your system complete protection, but its operations got limited when it comes to VoIP services. Old firewalls don't recognize the VoIP services and block the VoIP protocol from the system.

How to Fix: Get an up-to-date firewall that scans all the information without causing a packet loss or making the system slow.

3. Vishing:

Vishing is a VoIP-based phishing attack that is conducted by the phone. Scammers use a fake caller ID to make an illusion of calls coming from the local number.

If you don't answer the call, it will leave a voicemail asking you to call back. Sometimes, these types of scams also employee an answering machine or call center who is not aware of the crime. This scam aims to get information like card details, birthdates, account details, and more.

How to Fix: To prevent vishing, businesses should verify all phone requests, even if they look like coming from IT departments. Also, avoid tapping or clicking links in the messages. Don't share any personal information with the callers unless they are legitimate.

4. DDoS attack:

A distributed denial of service attack is a malicious attack where hackers use all the bandwidth from the data network, making it vulnerable.

Almost 70% of the organizations said they have experienced around 20 to 50 DDoS attacks in 2018-2021.

These attacks are carried out through a network of Internet-connected devices that become malicious and control hackers. In this, the controls of system admin come into the attacker’s hands, and everything gets controlled remotely.

How to Fix: DDoS relies on setting the traffic thresholds, so familiarize yourself with the inbound traffic. Also, keep your data and the Voice traffic separate so that the attack doesn't affect your business communications. You can do this by adding encryption software or by using a VPN. You can also use a VLAN (virtual LAN) to identify unauthorized data.

Apart from this, some other things you can do are:

* Add filters; this will tell the router to drop packets from the source of the attack.

* Don't let the webserver being overwhelmed; rate your router limit

* Close all the half-open connections

* Drop all malformed packages

* Set slower UDP and ICMP to drop thresholds

*Note: While these measures are somewhere effective, they do not guarantee to stop the DDoS completely. They will buy you little time to call a professional internet service provider.

5. Call Tempering:

Call tempering occurs when the data packets are sent in the same path that you are using for the calls. This makes disruptions in the audio signals causing delays and a long period of silence during the call.

While some people confuse it with mere annoyance, it can be disastrous for your business if the hacker gets into the VoIP to extract confidential information.

How to Fix: Unencrypted voice streams are more likely to get tampered with or hijacked, so use data encryption to keep hackers away. You can also prevent tampering by adding an extra layer of protection to the devices like IP phones. Using blockchain initiates the protocol authentication and prevents call tempering.


Voice Over Misconfigured Internet Telephones or VOMIT is software that gets voice packets and siphons information from a VoIP system. VOMIT converts a simple phone call into a .wav file that can be played on any device having media player software.

In other words, it's a type of eavesdropping that only hacks information from your system and gives the attacker access to information like passwords, usernames, phone numbers, and other details.

How to Fix: You can prevent this by using a hosted VOIP provider, which will encrypt all calls before sending. You can also consider setting up a private PBX network that provides more security than the public network.

7. Viruses and Malware:

Malware and viruses not only affect internet-based applications but also contribute to network security issues and VoIP. They damage programs by consuming network bandwidth and creating signal congestions. This causes signals to a breakdown in VoIP and corrupts data, creating a packet loss in the system.

How to Fix: IT teams should employ various data security measures like regular security checks and encryption to protect the VoIP system from viruses.

8. Service and Identity Theft:

An internet-based phone system is more vulnerable to fraud as compared to other traditional telephony services, with theft of service being the most common one.

The theft of service means hacking important information or services from a company without paying for it. It may involve changing invoicing records, deleting information, unauthorized invoicing, and more.

How to Fix: To prevent this, make sure your passwords are secure. Prevent unauthorized physical access by keeping the antivirus software up-to-date. Also, follow a fraudulent call routine detection and make sure to use encrypted software.


SPIT, Spam over Internet Telephony, is an undesired, automatic, and pre-recorded call that is made by using VoIP. It's like email spam in the form of a phone call. These calls create disturbances that are tied up with your virtual phone number.

How to Fix: To combat SPIT in VoIP networks, you can either use a content-based SPIT detection system or an identity-based SPIT detection system. The content-based detection system processes the voice streams for identifying the spam or phrase. The identity-based SPIT detection uses subscriber identity to monitor malicious behavior.

Even if you are safe and have not fallen victim yourself, the threats of security breaches are serious. Let's consider the importance of VoIP security!

Is My Voip Secure To Use Now?

Reading about all the security risks and dangers might make you feel worried about making Internet-based calls, but following some basic security tips will give you peace of mind that your business is safe and protected.

Let's have a look at them;

* Data Encryption is one of the most effective methods to secure your sensitive and important information.

* Using strong and verified passwords and not keeping the same password for every device

* Doing regular network tests for security vulnerabilities

* Updating your communication and data sharing tools/apps

* Training employees to identify the phishing attack


When using things connected to the Internet, you have to keep an eye on the risks and threats, and the VoIP system is no different. The more you incorporate it into your business, the more you should be prepared for its vulnerabilities. By increasing the level of security, you can prevent your business from most of the VoIP security risks.

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