Tech

The OpenSSL Heartbleed disaster

Published on:

April 11, 2014

For two years, a vulnerability in certain OpenSSL versions allowed attackers to intercept encrypted traffic, potentially exposing sensitive information like private server keys. This vulnerability, known as Heartbleed, caused a global security crisis. Despite OpenSSL’s open-source nature allowing scrutiny, the bug remained undetected, and there were rumors suggesting some may have exploited it rather than reporting it. Early on, Vodia focused on security, opting for a custom TLS implementation to avoid issues like OpenSSL's memory fragmentation. This decision not only helped sidestep vulnerabilities like Heartbleed but also shielded the PBX from widespread exploits, as attackers lack access to the source code.

For two years there was a leak in certain versions of the OpenSSL stack that made it possible to intercept the traffic that was supposed to be encrypted. And even worse, there are rumors that say that this leak made it possible to read the private key of the server. If that is really the case, this security is nothing short of a meltdown of global security. In any case, it is definitively an epidemic failure. The effects of this will continue to ripple through the system for the coming weeks. Brace for more news.

Starting at the times of pbxnsip, security was a focus from the first days when we were working on the PBX. It would have been easy to use OpenSSL; it would also have had the advantage that we can easily FIPS certified. However there were drawbacks with OpenSSL. Our main concern was memory fragmentation because of the way OpenSSL was allocating memory that cannot be moved by garbage collection. Our PBX was designed to run for a very long time, and that has consequences for the memory allocation. Using C-style pointers makes that goal hard to achieve.

As a side effect, we used a buffer class wrapper that was protecting the code from accessing memory outside of the allocated memory for a variable. That was exactly what happened in the Heartbleed bug. If someone sent an index that was out of the boundaries of the memory that was allocated for the request, the OpenSSL code did not properly check if the index is within boundaries and reveal information that was supposed to stay private.

Open source has the advantage that a lot of people can take a look if the code works correctly and there are no backdoors in the code. In this case that did not help. I am afraid that it actually made things worse. It could well be that programmers who found the bug in OpenSSL code did not report the problem; instead they joined the dark side and exploited it. Giving the bad people the source code of such a critical component of the Internet had a disastrous effect. This explains why we had so many news about stolen passwords recently where nobody had a good explanation how this could happen.

I am not even sure if we need to count the people working for NSA and other government agencies around the world as bad guys. If we assume that they knew about the vulnerability for some time, not telling the public about the problem gave them for sure an advantage in accessing information that would otherwise not be accessible. However if that’s the case they accepted the huge collateral damage of others continuing to exploit the vulnerability, which is in my opinion unacceptable.

The main advantage of the Vodia PBX using its own TLS implementation is simply that it is not mainstream. This keeps it relatively safe from epidemic failures. Although we don’t know it, we can assume that that implementation is also not free from errors. But programmers who think about attacking the PBX don’t have the source code to find open doors. Finding out without the code is difficult, and definitively not low-hanging fruit.

Latest Articles

View All

Webinar | Real-Time Media Streaming in Vodia PBX: AI, Call Transcription, and Security in V69.5.6

Join Vodia Networks on April 8 for a live, in-depth webinar on how real-time media streaming is powering the future of voice communication. Discover how Vodia PBX version 69.5.6 enables seamless AI integration, live call transcription using the Whisper API, and secure voice data handling. Hosted by Sales Engineer Eric Altman and VoIP Engineer Hamlet Collado, this session will walk you through real-world use cases, including OpenAI and Google Speech-to-Text integrations, MS Teams support, and new security features. You’ll also get a first look at Vodia’s AI roadmap and have the opportunity to ask your questions during a live Q&A.

March 28, 2025

The Vodia PBX On-Premise Whisper AI Deployment​

Whisper, OpenAI’s Automatic Speech Recognition system, delivers multilingual, noise-tolerant, and technical-language-ready transcription through a streamlined encoder-decoder architecture. With Vodia PBX’s integration, organizations can choose between using OpenAI’s service or hosting Whisper AI locally for complete data sovereignty and control. This on-premise option ensures that sensitive call data stays within your infrastructure while still benefiting from powerful transcription capabilities. To explore deployment options, see our Whisper AI on-premise setup documentation, review a self-hosted integration example, or follow our cloud-based call transcription guide.

March 27, 2025

Vodia at Enterprise Connect 2025: Embracing AI and Advancing Communications

Vodia Sales Engineer Eric Altman attended Enterprise Connect 2025 on March 18 and 19, where he connected with partners and gained insight into the future of enterprise communications. AI was the clear focus of the event, with discussions centered on agentic systems, chatbots, and generative technologies. “It was certainly the main element in the atmosphere,” Eric noted. He also shared his excitement about Vodia PBX version 69.5.6, which includes real-time AI integration with OpenAI and call transcription using the Whisper API. The event confirmed that AI is rapidly becoming a core component of modern communication platforms—and Vodia is well-positioned to lead the way.

March 26, 2025