If you think Voice over Internet Protocol (VoIP) security is simply about setting a strong password, think again. In 2025, threats against VoIP systems have become more sophisticated, necessitating advanced safeguards and strategies. But don’t fret. Here are six practical ways to secure your VoIP environment and stay one step ahead of cybercriminals.
Enable multifactor authentication (MFA)
Strong passwords alone can’t protect your VoIP systems. It’s high time you implement multifactor authentication (MFA), which adds a second step — usually a temporary code, biometric scan, or authentication app — to ensure only authorized users get in. MFA protects VoIP portals, web-based dashboards, and softphone apps from two common types of cyberattacks:
- Brute-force attacks, where cybercriminals use automated software to guess your password over and over again until they get it right.
- Credential-stuffing attacks, where attackers use lists of usernames and passwords stolen from other websites to try and log in to your account, hoping you’ve reused the same credentials.
Require true end-to-end encryption
Your VoIP provider should offer end-to-end encryption that covers both call signaling and media (the actual voice or video content). End-to-end encryption means that the data is scrambled and indecipherable from the moment it leaves your system until it reaches the recipient’s device, making it virtually impossible for anyone to eavesdrop or intercept your communications.
Encryption is especially vital for the healthcare, legal, and finance sectors, where voice communications often involve sensitive and confidential information.
Use virtual private networks (VPNs) the right way
VPNs are a reliable way to secure VoIP traffic, particularly for employees working remotely or using mobile devices, as they create a secure, encrypted tunnel between the user and your internal VoIP infrastructure. But simply installing a VPN isn’t enough. It needs to be properly configured, regularly updated, and paired with strong access controls. A poorly maintained VPN can become a point of entry rather than a security tool.
Turn off the phone’s web interface
Many VoIP desk phones include a web-based interface that allows users to tweak settings from a browser. But unless your team actively uses this feature, it should be disabled. Keeping the web interface open, particularly without robust authentication measures, poses a significant security risk. Hackers can exploit it to access user accounts, alter forwarding rules, or even listen in on calls.
Set up a VoIP-aware firewall
Not all firewalls are designed with VoIP in mind. VoIP traffic uses specific protocols like the Session Initiation Protocol, which requires a firewall that understands how to handle and filter these communications.
Use only next-gen firewalls with built-in VoIP-specific protections as part of their core features. These firewalls can detect spoofed calls, prevent denial-of-service attacks, and detect unusual usage patterns that could signal abuse. Some can even terminate suspicious sessions in real time.
Monitor systems 24/7
VoIP attacks often happen outside regular business hours, typically late at night or over the weekend when systems are less closely monitored. Cybercriminals take advantage of these quiet periods to commit toll fraud, access sensitive call records, or identify system vulnerabilities. This makes round-the-clock monitoring essential for safeguarding your communications.
Implement tools that detect unusual call behavior, such as spikes in international calls, repeated login attempts, or connections from unfamiliar locations. Better yet, partner with a managed IT provider like us. We can help you set up these tools while offering 24/7 VoIP-aware monitoring and rapid incident response.
Not sure where your VoIP security stands? Contact us. We can conduct a simple audit or a consultation to uncover VoIP vulnerabilities, enabling you to fix them before they’re exploited.