A few days ago as part of my many responsibilities I stumbled upon what appeared to be a directory traversal. At first I did not believe it, partially because the specific class of vulnerability is quite dated and partially because I couldn't believe that I had been working with this product for so long and hadn't stumbled upon it.
Unfortunately, Splunk is about 170Mb of python, shell scripts and stripped binaries, so debugging this was no easy task. I actually thought I got lucky and traced the problem to an old version of TwistedWeb that Splunk uses to power the web server, but it turns out I was wrong. Furthermore, finding a python HTTP project that used an equally old version of TwistedWeb was basically impossible, so I was stranded.
At around the same time I opened an FYI ticket with Splunk giving them a heads up. Not only did they appreciate the information, they followed the TwistedWeb ticket and quickly determined that this was their bug, not Twisted's. A patch was quickly published and it is an easy update for anyone who is crazy enough to expose their Splunk server to the outside world.
This a great example of two things.
First, old bugs die hard. This was a classic example of a URI encoded directory traversal (%2e%2e%2f %2e%2e%2f %2e%2e%2f, aka '../../../../'), which Wikipedia describes fairly well. Exploiting this requires no authentication and simply requires that you have an HTTP client and the ability to reach the Splunk server.
Second, it is important to have a mechanism within your organization that allows security information to be channeled to the correct people in a timely manner. How many times can you recall where you call or email vendor XYZ and they basically refuse to speak to you unless you are a paying customer? Not addressing security issues in your products not only makes you look bad in the eyes of the security community, it also damages your brand and puts your paying customers at risk. Splunk is a great example of process done right.
Security is you friend.