What Are the Most Common VoIP Security Vulnerabilities?

Businesses have moved into a more digital environment over the past decade and a half, and many have made the switch from physical landline telephone service to Voice Over Internet Protocol (VoIP) technology. While VoIP is a smart move that offers a long list of distinct benefits, it doesn’t come without its own set of security concerns. The more prepared your business is for VoIP cybersecurity, the more you’ll be able to leverage the advantages that VoIP provides.

The Power of Hosted VoIP Phone Services for Businesses

VoIP doesn’t just compete with traditional landline phone systems—most of these platforms blow old school phone systems out of the water. The real power of VoIP lies in the following benefits:

Lower Costs

VoIP is significantly less expensive than a traditional phone system. This is largely due to lower installation and maintenance costs. You don’t have to purchase a bunch of expensive equipment or hardwire your office—you just pay an affordable monthly subscription rate.

Remote Friendly

In this age of remote working and virtual business models, having a physical landline in one office location doesn’t make a whole lot of sense. VoIP gives each employee the ability to access the phone system regardless of where they are.

Useful Features

VoIP systems offer different features that traditional landline phone systems do not. This includes IVR menus, automatic call recording, dynamic voicemail, and other customer features. With all of these benefits, is it any wonder that 61 percent of businesses have already switched to a VoIP system? Millions of additional VoIP subscribers will be joining the fold in the coming 18 months. With all the benefits VoIP can provide, it’s critical that you understand how to secure a VoIP system.


With VoIP, it doesn’t matter if you have 10 employees or 1,000. You can easily scale up or down to account for growth or contraction in your business. It’s simply a matter of logging into your account and pressing a couple of buttons to optimize your plan.

VoIP Security Threats To Be Aware Of

Business owners are focused on phishing, email security, and cloud security. Yet, most are not aware of the fact that there are cybersecurity risks for VoIP as well. As a result, they fail to plan properly and don’t implement the correct security measures and oversight. Don’t let this be you. It’s time to get familiar with some of the specific threats that are present with VoIP.

1. Denial of Service (DoS) Attacks

DoS attacks have been happening for years. They’re fairly rudimentary and don’t require much sophistication on the part of the hacker—yet they can wreak havoc on your business.

DoS attackers will target VoIP systems because business owners often leave their Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) ports at risk. When they’re ignored, hackers can overwhelm the VoIP server with Session Initial Protocol (SIP) messages. As they flood the VoIP server, the system slows down and can even stop completely due to the onslaught of traffic.

2. Viruses and Malware

Did you know that viruses and malware can actually affect your VoIP network, just like your computers and servers? We’ll save you the technical explanation of how malware and viruses can find their way into your network, but just know that they can perform costly and unwanted system interruptions. Some are even capable of sabotaging sensitive information, stealing protected data, and taking over entire computer systems.

Most viruses and malware can be prevented with proper employee training and awareness. There are also effective anti-virus software solutions that extend to protect VoIP vulnerabilities.

3. Vishing

You might be familiar with email phishing, but what about vishing? This is the voice-based version of phishing. It refers to a category of schemes and fraud tactics that hackers use to trick employees and gain access to sensitive information, accounts, and systems.

Generally, vishing incidents start with someone targeting financial or personal details that can be easily manipulated. They’ll call in and use tricky schemes to gain access to passwords and other information (often posing as someone else). Be wary of receiving voicemails or electronic messages that claim an “account security” threat and leave a callback number. Calling these numbers may inadvertently connect you to the hacker’s private VoIP system, which can record sensitive pin codes and account details.

4. Phreaking

Phreaking happens when a hacker accesses your VoIP network and uses it to their advantage. This form of fraud focuses on stealing data from the service provider and/or racking up extremely expensive network calls. In some cases, the threat actor can even change your plan, add credit, remove credit, or make expensive changes to your bill that you won’t be aware of until it’s processed.

5. Eavesdropping

This is one of the more common call fraud techniques targeting VoIP phone systems. As the name suggests, hackers will gain access to VoIP calls, listen in, and steal data. They’ll also capture unencrypted VoIP traffic without permission. The problem with eavesdropping is that you don’t know it’s happening. Hackers have almost unlimited resources and will listen to thousands of hours of calls if they need to in order to access details and passwords they can use to further compromise your business.

Strengthen Your VoIP Security With The Millennium Group

Being aware of the VoIP threats you face is the first step. The second step is to take preventative action to ensure you aren’t a victim of these schemes. This includes using stronger passwords, regularly updating your system, carefully monitoring your call logs, and setting up stronger policies for employees (particularly remote ones). It also means selecting the right VoIP provider.

At The Millennium Group, we’re more than just another VoIP provider. In addition to providing world-class business phone systems that are affordable and scalable, we also place a significant emphasis on VoIP security. With our hosted VoIP solutions, you never have to worry about being exposed to the security issues mentioned above. We’re fully aware of these threats and proactively work to protect your clients against any and all vulnerabilities.

Want to learn more about how the right VoIP phone system with integrated security can put your business on a positive trajectory for the future? Give us a call today—we’d love to chat about it!

Dialing a telephone in the office