How SMBs can prevent VoIP eavesdropping

Posted on Wednesday April 14, 2021

As a business owner, you should be aware of the different cyberattacks that can hurt your company. One of these is Voice over Internet Protocol (VoIP) eavesdropping. This occurs when cybercriminals infiltrate your VoIP network and listen in on your calls in hopes of stealing critical business information. To prevent this, you should implement the proper defenses for your VoIP phone systems.

Change the default configurations of your VoIP system

Using your VoIP phones without changing the default configurations can be the worst mistake you can make. These days, it’s easy for hackers to search vendor documentation for things like default usernames and passwords. Depending on your VoIP provider and phone model, you should have the option of changing the default login credentials on your handsets.

Get updates from your handset vendor

In 2015, Cisco detected vulnerabilities in their VoIP phones that enabled attackers to listen in on phone conversations. Cisco quickly released security alerts to inform their customers about these vulnerabilities, giving them enough time to address the issues. The lesson here is you must regularly monitor advisories from your hardware vendor or work with an IT provider that does so for you. Without proper monitoring, you won’t know how susceptible your corporate VoIP phones are to eavesdropping.

Update session border controllers

Another way to combat VoIP eavesdropping is to constantly update your session border controllers (SBCs). By doing so, you’ll be updating your VoIP’s antivirus software, which means your systems are better protected from constantly evolving cyberthreats. Routine SBC updates are essential for securing SIP trunking as well as responding to new threats.

Encrypt VoIP calls

If you work in a regulated industry like healthcare or finance, encrypting VoIP calls is essential to staying compliant. Work with your VoIP provider and auditors to determine the best encryption options for your communications infrastructure. Many cloud VoIP providers offer call encryption guidelines, and some even offer it as a premium service.

Build a hardened VoIP network

Make sure your VoIP network has:

• IP private branch exchange (PBX) using minimal services, so that the hardware can only power the PBX software
• Firewalls with access control lists set to include call control information
• Lightweight Directory Access Protocol lookup, and signaling and management protocol
• Reinforced endpoint security with authentication at the endpoint level

To effectively defend against VoIP eavesdropping, businesses need to take a holistic approach to cybersecurity. This includes enforcing policies, deployment, and security practices that will keep malicious agents out of your network. Feel free to contact us for further information on how to protect your business.