We (at PROTOS research) released our first free VoIP fuzzers in 2002, and were amazed by the success! Everyone seemed to immediately adapt them into their quality assurance and security assessment practices. Some people still use them!
We (at Codenomicon) simultaneously released a commercial fuzzer. A number of other security companies have also released their own versions, some good, but most of them worse than even the first original release by us (IMHO).
What have we learned during these six or so years of proactive security work with VoIP fuzzing? Here is my top ten discoveries.
A free open source fuzzer will be used by everyone. Provided the tool is easy to use, and easy to integrate in your processes, there is no reason not to use it.
After tools are used by end users of VoIP, the market creates a requirement for manufacturers to also use the tools. Carriers and service providers have done a good work at this.
#3 Poor consumers
Nobody cares for consumer products, or so it appears. Unfortunately there is no market requirement for testing consumer products.
#4 Open source projects
Let's face it, there is no test tool budget for FOSS (free open source software). Fortunately some government agencies and service providers depend on these products, and sometimes contract people to test some of them.
Interesting studies on fuzzer coverage are mostly ignored by the industry. This might be due to bad requirements from the customers, i.e. if any fuzzer will do, then the cheapest is used.
Vulnerability disclosure has no influence on fuzzer usage. Free testing is free testing. When other people fuzz the product, and report problems, people think that the work is done for them.
#7 Forums have failed
Quality assurance forums have not yet found security testing. Security forums do not care for tools, but are services driven.
Almost all certification efforts are commercially driven, and do not provide an open forum where the differences between fuzzing techniques can be discussed. Participation in expensive and closed. All certification efforts have failed. People shop for easiest certification levels, not the best ones.
There are no accepted metrics for fuzzing.
Who should do fuzzing, and when. Nobody knows.
So what is the status of VoIP fuzzing today? It is still an emerging business where the key driver for adaptation is responsibility of the actors involved. You do not need to do it, but if you do then the results will be extremely positive. Fuzzing provides a competitive edge that you do not necessarily want to share with your competitors.