Understanding VoIP (Voice over Internet Protocol) and Messaging Vulnerabilities

Part One

You may think of email, firewalls, or endpoint protection when you imagine your security perimeter. But in today’s world, voice calls, chat apps, and real-time collaboration tools are equally rich targets for attack. Every call, every message, and every digital conversation is a potential point of compromise. Secure messaging and VoIP (Voice over Internet Protocol) create a critical barrier between your systems and your people, the final line of defense. By securing how your teams communicate, you help ensure that human trust can’t be turned into an attacker’s greatest weapon.

Why This Matters: The Rising Stakes in Communications

Organizations now rely heavily on voice, video, chat, and collaboration tools such as Slack, Teams, Signal, and Zoom to stay connected and productive. Unfortunately, attackers are well aware of this reliance and often exploit misconfigurations, protocol weaknesses, or weak encryption within these platforms. With access to call metadata, message contents, or call routing information, a malicious actor can eavesdrop on conversations, impersonate users, intercept authentication tokens, or even manipulate communications in real time. 

Human trust and voice communication create a uniquely dangerous threat vector. We’re naturally inclined to believe the person on the other end of a call, especially if they claim to be a trusted colleague, IT staff, or an executive. When that trust is paired with a compromised VoIP channel, it becomes a powerful tool for attackers. They can spoof internal extensions or phone numbers to appear legitimate, inject or alter messages mid-call—such as instructing someone to “change the bank account to…”—or launch sophisticated voice-phishing (vishing) attacks using intercepted or manipulated context. In some cases, attackers can even coerce employees into taking risky actions during live conversations, turning a simple phone call into an avenue for exploitation. 

Compliance, Privacy, and Legal Risks

Many regulated industries treat communications (calls and messages) as sensitive data. Failure to properly secure communications can result in serious compliance, legal, and contractual risks, including:

• Data privacy violations under regulations such as the General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA) if user messages, call logs, or recordings are exposed.
• Noncompliance with industry regulations (e.g., HIPAA in healthcare, FINRA in finance) that require secure communication channels, encryption, and proper logging or audit trails.
• Legal and e-discovery challenges if communications are subpoenaed and lack verifiable integrity or non-repudiation.
• Breach of contractual or client obligations that mandate secure handling of sensitive information, such as personal data, trade secrets, or financial details.

Simply put: if communications are unprotected, organizations may be held liable not only for breach damage, but also regulatory fines, litigation, or breach of contract.

Real-World Incidents

In recent years, several real-world incidents have shown how easily insecure communication systems can be exploited. Attackers have hijacked VOIP and PBX systems to make fraudulent long-distance calls, intercept conversations, and even use stolen call data for further social engineering. Others have taken advantage of compromised internal networks to spoof executive numbers, tricking finance teams into processing fake wire transfers.

Even trusted collaboration tools aren’t immune. In 2024, Disney suffered a massive leak of internal Slack data, exposing more than 44 million messages and other confidential materials after hackers breached the company’s workspace — a stark reminder that everyday chat tools can carry enormous risk if misconfigured or compromised. Similarly, a Microsoft data exposure in 2023 accidentally revealed tens of thousands of internal Teams messages, highlighting how even well-resourced organizations can fall victim to simple configuration errors..

Together, these examples illustrate how vulnerable voice and messaging systems can become when communication security is treated as an afterthought.

Why SMBs Are Especially at Risk

For small and mid-sized businesses (SMBs), these risks can be even more severe. Many smaller organizations depend on cloud-based VoIP and messaging solutions because they’re affordable and easy to deploy, but that convenience can come at the expense of proper configuration and oversight. With limited IT resources and no dedicated security staff, SMBs often rely on default platform settings or assume that providers handle all the security behind the scenes.

Cybercriminals are well aware of this gap. They increasingly target SMBs as entry points into larger supply chains or as low-effort, high-reward victims. A single compromised call, message thread, or account can lead to fraudulent payments, leaked client data, or extended downtime. For SMBs, secure communication isn’t just a matter of privacy or compliance; it’s essential to maintaining operations, customer trust, and business continuity.

Building Awareness Around Secure Communication 

While this article focuses on why secure communications matter, awareness is the first defense. Your voice and messaging tools are part of your network and should be protected with the same care as your email and endpoints. 

Start by: 

• Evaluating your tools. Know which platforms your teams use and how they’re configured. 

• Checking security basics. Confirm calls are encrypted end-to-end, chat logs are stored securely, and user access is properly managed. 

• Limiting exposure. Review integrations, restrict unnecessary data retention, and keep permissions current. 

• Partnering with experts. A trusted IT provider can help identify gaps and secure configurations before attackers do. 

Finally, make communication security part of your culture. Encourage employees to question unusual requests, even if they come from “familiar” voices or chats. Awareness and skepticism are powerful defenses against social engineering. 

In Part Two of this series, we’ll explore how to build a secure communications foundation, from encryption and identity to monitoring, policy, and training. 

Conversations Are the New Frontier

In the ongoing cybersecurity battle, we tend to focus on email, network firewalls, and endpoints. But reality is, voice calls and real-time messaging are now frontline weapons for attackers. By treating secure messaging and VoIP as first-class security concerns, organizations can raise the cost for attackers dramatically. 

At PulseOne, we help organizations secure every conversation. From protecting your VoIP and messaging systems to ensuring your communication tools, policies, and configurations align with today’s evolving threat landscape, we provide the expertise to keep your human and technical defenses in sync. If you’re ready to safeguard how your teams connect and stay ahead of emerging communication threats, contact PulseOne to get started.

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PulseOne is a business services company delivering information technology IT management solutions to small and mid-sized businesses for over 20 years. In short, we’re your “get IT done” people.

We are passionate about the power of PEOPLE and TECHNOLOGY to transform a company. We are confident we can significantly accelerate your PROGRESS towards your business technology objectives.

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