Top VoIP security risks and how to avoid them

April 19, 2023

VoIP, just like other applications, has its own security risks. However, these problems can be easily tackled with a few preventative steps around common issues like phishing.

The bOnline team has put together this article to help you recognise what risks there are with VoIP and how to minimise them.

How secure is VoIP?

VoIP (Voice over Internet Protocol) allows you to make and receive calls over the internet. This is different from traditional landlines which use copper wires.

More and more individuals and businesses are turning to VoIP due to the improved sound quality, often lower cost and a wider range of VoIP features. Traditional landlines are also set to be switched off by 2025, making it all the more important to consider your options now.

Are VoIP calls secure? 

As long as all the right measures are in place, VoIP calls are very secure. Encryption technology has moved on a lot in recent years which means interception or unauthorised access is becoming much harder. In addition to this, regularly updating and maintaining your VoIP system can reduce the chances of vulnerabilities that hackers can exploit.

The most common VoIP security threats

It’s well worth familiarising yourself with some of the most common VoIP security threats, including:


As VoIP calls are transmitted over the internet, anyone can potentially listen in if your calls aren’t encrypted effectively. Hackers may intercept and eavesdrop on VoIP calls, allowing them to get hold of private information like bank details, customer data and security numbers.

Caller-ID spoofing

Caller-ID spoofing involves attackers manipulating the caller ID information so that their identity isn’t revealed. In other words, someone receiving a call may recognise the number on their screen, therefore believing the call to be genuine when in fact it’s not. It’s a common tactic used by fraudulent callers or people looking to initiate phishing attacks.

Denial of Service attacks (DoS)

DoS attacks happen when cyber attackers bombard your service with traffic. They continue to do this so much that it subsequently crashes and then becomes unavailable. This can spell disaster for your business as no transactions can then be made through your website which can cost you serious money. On top of that, your customers won’t be too happy either, potentially causing damage to your reputation along the way.

Toll fraud

Toll fraud happens when scammers hijack an organisation's VoIP system and make unauthorised long-distance calls. This can often cost the victim thousands of pounds. Small businesses especially can be ruined by toll fraud, especially if they heavily rely on VoIP for communication.

Phishing attacks and malware

Malware and phishing attacks are not uncommon with VoIP systems and are designed to steal sensitive information. There are many different types of malware, including viruses, spyware and trojans. Any of these can infiltrate your network, stealing data and causing extensive damage.

Man-in-the-middle attacks

Man-in-the-middle attacks are when attackers intercept a call before stealing, altering and destroying the information being transmitted. With VoIP, it means that hackers can redirect conversations to a different server, allowing them to listen in and record your conversation.

VoIP vishing scams

Vishing scams (Voice Phishing) use VoIP technology to trick people into giving out sensitive information. Fraudsters will make a VoIP phone call and impersonate well-known legitimate companies like government bodies, insurance agencies or banks. They then ask for personal details like card numbers, your mother’s maiden name, security information etc.

How to secure VoIP 

There are several things you can do yourself to help keep your VoIP call secure. They include:

Updating software regularly

Make sure all VoIP software is up-to-date with the latest security updates, fixes and patches.

Verifying users

Ensure all users verify their identity using water-tight authentication protocols before they can access the VoIP network.

Using strong passwords

Strongest passwords possible should be used when logging into the VoIP system and any other associated accounts. It’s always worth using a combination of upper and lower case letters as well as numbers and symbols. Also, make sure each password is different for every application; it’s tempting to use the same password for everything but it’s a much less secure way of protecting yourself.

Encrypting data

All data that’s being transmitted over your network should be encrypted and backed up by strong encryption protocols.

Implementing firewalls

Firewalls are a very effective way of preventing unauthorised access to your VoIP network. 

Monitoring your VoIP network

Keep an eye on your network for any anomalies or suspicious activity. If you see something amiss, investigate it and take action immediately.

Carrying out security awareness training

Your employees and other business stakeholders should understand the importance of security threats and how they can be prevented.

Limiting access

Be very selective about who can access your VoIP network. If possible, keep it to authorised employees only. If an employee leaves the business, delete them off the system straight away.

Use the most secure VoIP provider

There are many different VoIP providers out there so you’ll need to do your homework when choosing the ideal one for your business. However, the best ones will always prioritise uptime, reliability, security and customer service above everything else.

At bOnline we know that balancing quality and price isn’t always easy. That’s why we offer a free 7-day trial so you can quite literally try before you buy. It’s a great way to test out all the great VoIP features on offer, plus why not also see our latest case studies too.

Got a burning question or want to see how a bOnline VoIP system could move your business on to the next level? Call us on 0204 586 7064.


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