Understanding VoIP security risks, and how to mitigate them, is an important part of choosing the right phone system for your business.

What Every Business Should Understand About VoIP Security

Laurah MwirichiaLast updated on September 5, 2023
7 min

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VoIP has become so ubiquitous since its humble beginnings that it’s difficult to imagine doing business without it. The benefits of VoIP, including its simplicity, versatility, flexibility, and affordability, make it an invaluable piece of technology for individuals and businesses across fields. However, as the technology evolves, so do the questions surrounding VoIP security.

How to Gauge a Vendor’s VoIP Security

In many ways, VoIP is just as secure as traditional telephone communication. But that doesn’t mean you don’t have to take VoIP security seriously. Here are four security measures you should look for in a VoIP provider:

Adherence to Information Security Frameworks

One simple way to evaluate a provider’s VoIP security is to examine which, if any, international information security frameworks they follow. These frameworks are developed by international organizations and set the standards for what companies should be doing to keep data safe and secure. Adopting these standards is rarely mandatory, so screening for them can help you choose a provider who cares deeply about keeping their clients’ data secure.

A few examples of common security frameworks are ISO 27001, ISO 27002, SOC 2, and PCI/DSS.

Encrypted Customer Data

Encryption ensures that even if a hacker gains access to VoIP content, they won’t be able to understand it, which will keep private information safe. When judging a VoIP provider’s encryption processes, there are a few key terms you should look out for.

The provider should be encrypting all communications with the most recent TLS protocol, for instance. Calls made using the WebRTC protocol, which enables an exchange of data between two users over the internet, should be encrypted automatically from beginning to end.

A VoIP system’s session initiation protocol, or SIP, is a protocol that facilitates the beginning and end of every VoIP call you make. And according to a 2020 report by PCMag, SIP can be a VoIP system’s biggest security vulnerability—because it wasn’t created with security in mind. To strengthen this weak point, VoIP providers should encrypt connections at both ends as well as the call content itself.

Data Centers With Comprehensive Security

The provider should use cloud computing services with secured data centers, such as Amazon Web Services (AWS), Microsoft Azure, or IBM. Your cloud computing vendor should also conform to the information security frameworks discussed above.

Dig into each prospective vendor’s security page and compare to determine which is the best fit for your business.

Monitoring Systems That Flag VoIP Security Issues Before It’s Too Late

The right provider will have infrastructure in place that allows them to monitor VoIP call traffic and data to keep an eye out for anything suspicious. Providers may monitor:

  • The types of calls, callers, and devices used for calling

  • The times and locations of callers (you can often set your own parameters around these with your VoIP software)

  • The total amount of call volume at any given time

  • Irregularities in calls that could indicate a hacking attempt

This can be accomplished by a VoIP phone system enabled with advanced call analytics.

For full transparency, you can review Aircall’s commitment to VoIP security here, addressing all the security issues we mentioned here.

Is VoIP Secure? 3 Common Risks to Your Business

From small businesses to large, multi-billion dollar companies like Yahoo, Target, and JP Morgan Chase, every business can be susceptible to attacks on its digital infrastructure. Knowing how to handle these security breaches is critical to a business’s success and longevity.

We will tackle some of the biggest VoIP security issues and find out what you can do to protect your business from attack.

Denial of Service (DoS)

What it is: Denial of Service is one of the most common security concerns for business networks. The end goal of any DoS attack is to overwhelm a system with so many requests that it slows down and or is even forced to stop entirely. Media streaming sites are some of the most common victims.

For a DoS attack on a VoIP system, hackers use an automatic phone dialer that rapidly calls and hangs up. This keeps your line too busy to accept other calls, which can clog your business phone lines and bring your operations to a grinding halt.

How to Prevent it: There are many new security protocols available that can help protect your communication infrastructure against attackers. One example is using Session Border Controllers (SBCs) that act like a VoIP firewall. SBCs protect your network by building a secure connection between you and your service provider while giving you more control over your VoIP calls and voice traffic.


What it is: Often used for identity theft, eavesdropping on VoIP calls usually involves tapping into an unencrypted call while it’s being transmitted over your internet or data network. Without encryption, cybercriminals can more easily intercept sensitive customer information such as names, birthdates, banking information, and passwords.

How to Prevent it: These days it’s easier than ever to set up data and voice encryption to strengthen your VoIP security. Here are a few simple ways:

  1. Transport Layer Security (TLS): This secures incoming and outgoing traffic between callers to prevent eavesdropping.

  2. Secure Real-Time Transport Protocol (SRTP): This encrypts data packets transmitted during calls so that eavesdroppers cannot decipher them.

  3. Virtual Private Network (VPN): This provides a secure, encrypted tunnel that allows you to transmit and receive data safely.

Malware (Viruses, Worms, Trojans, and Bots)

What it is: Viruses and other malware have been around for about as long as computers themselves. Over the years, attackers have developed ever-more creative ways to exploit vulnerabilities and spread malware that can damage software, access information, and steal data. Because VoIP relies on a web connection, it is susceptible to malware threats.

How to Prevent it: Your first line of defense when it comes to malware is safety training. Ask your VoIP provider if they include safety training as part of their onboarding service. Even if they don’t, take the time to educate your employees so they understand VoIP security basics, like never to open links or attachments that look suspicious or come through unknown senders. Inform them about the security risks of using free Wi-Fi hotspots with unsecured networks. Make sure they understand the importance of keeping their software up to date at all times. These seemingly small moves can go a long way toward lowering the risk of security breaches.

Strong firewalls will also help you combat malware threats to your VoIP system. Firewalls have a high security ROI: They’re simple to put in place but are one of the most effective security measures you can take. Firewalls act as gatekeepers that filter information as it passes from the internet into your voice network. If a firewall flags an information packet as “suspicious,” it will block it from entering your network.

Reducing Unknown Risk

While Denial of Service attacks, malware, and eavesdropping may be the most common risks surrounding VoIP technology, your system will be vulnerable to other types of attacks, as well. While you can’t always protect yourself against every single threat, there are many precautions that can help keep you safe.

Administer Ongoing Trainings

When thinking about how to secure VoIP phone systems, the most important step is to educate yourself and your team. Stay current on new and changing security threats and how you can prevent them.

Train your staff about secure data storage, encryption, and information organization. This is especially vital for employees who handle sensitive data.

Finally, always be prepared for the worst. No matter how safe we are while using the internet, sometimes cybercriminals are one step ahead. Have a contingency plan in place and educate employees on how to detect and handle security breaches. The last thing you want is someone accidentally causing more damage when something goes wrong.

Secure Your VoIP Phone by Securing Your Passwords

Secure passwords are the single most neglected area when it comes to VoIP security. You can invest in the best high-end encryption and gateway security tools, but all that won’t matter much if the smartphones, tablets, and computers that access your network use weak passwords.

VoIP works by transmitting information through online networks rather than individual, physical phone lines. That means if a hacker has access to one employee’s credentials, that person can threaten your entire business’s security. A hacker can install malware on devices that aren’t adequately protected and instantly access phone conversations and other customer data.

Teach your employees the importance of using long, complex, unique passwords on their work devices—passwords that they don’t use anywhere else. Encourage them to change those passwords at regular intervals. Make two-factor authentication mandatory when you can.

Monitor for Unusual Activity

Learning what is normal and abnormal in your network takes time and skill, but having monitors in place is vital to preventing attacks. Thankfully, there are many services that can detect fraudulent activity, flag it, and even halt it completely.

In addition to automated protection, growing companies should strongly consider hiring an IT manager to help monitor network activity. Not only will this person be able to point out irregularities that may be missed by automation, like strange calls, but they can also set an overarching security strategy for your business that adapts to changing threats, which will set up your company for success in the long run.


Having the ability to connect our business tools to the web is an amazing feat of modernization. We’re more efficient than ever, and businesses can scale while delivering incredible services to customers at a lower cost.

While VoIP security threats remain a valid concern for any manager or business owner, the most important thing is to be proactive. Staying prepared through ample training, vigilant monitoring, and robust defenses can keep your business safe and put your mind at ease with a secure VoIP phone system.

Published on July 8, 2020.

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