Skip to main content

2.2250738585072012e-308

Meet my new friend 2.2250738585072012e-308, We've been hanging out recently. If you've not heard of him, he's about ten years old but thats pretty old in [dog and in] software years. He's getting pretty famous in his old age, but he had humble beginnings as a lowly bug report on a Sun Microsystems website.

It's rumoured he was first discovered back in 2001, but his big break didn't come until recently, when it was realised that he has the potential to be a key component of a Denial of Service attack that could bring down many java based systems [that accept floating point numbers as input]. This includes commonplace application servers like Tomcat, who accept floating point numbers as part of the HTTP protocol.

2.2250738585072012e-308 has now been placed firmly in my mental bag of tricks along with divide by zero, 2^32, null, imaginary numbers, localised floats and all the others that routinely get brought out to help me test and investigate software.

But why am I doing this now? This information has been around for years. The software has been vulnerable for years. The hard work was done 10 years ago when some clever person found this bug. Their good work was ignored, by us... by me. I've added that bug to my toolkit, that should help me catch a few instances of it as time goes by. But if we think like testers - about testing - for a moment. I'm behaving as if I'm back on the happy path: "I know about all the 'typical' bugs again." But what other bugs are there?

The most effective way to learn from this is to not only take note of this instance, but to learn how to get even better from the experience. People like Sun (now Oracle), and other organisations, publish lists of bugs found by their community. Even better they often publish lists of 'recently' fixed bugs! So you can find a bug and suggest a solution! So now I'm going to start browsing these sites for useful intel' on the systems I'm testing. I recommend you do to.

Comments

Popular posts from this blog

Betting in Testing

“I’ve completed my testing of this feature, and I think it's ready to ship”
“Are you willing to bet on that?”
No, Don't worry, I’m not going to list various ways you could test the feature better or things you might have forgotten.
Instead, I recommend you to ask yourself that question next time you believe you are finished. 
Why? It might cause you to analyse your belief more critically. We arrive at a decision usually by means of a mixture of emotion, convention and reason. Considering the question of whether the feature and the app are good enough as a bet is likely to make you use a more evidence-based approach.

Why do I think I am done here? Would I bet money/reputation on it? I have a checklist stuck to one of my screens, that I read and contemplate when I get to this point. When you have considered the options, you may decide to check some more things or ship the app. Either could be the right decision.
Then the app fails…
The next day you log on and find that the feature is b…

A h̶i̶t̶c̶h̶h̶i̶k̶e̶r̶'s̶ software tester's guide to randomised testing - Part 1

Mostly Harmless, I've talked and written about randomisation as a technique in software testing several times over the last few years. It's great to see people's eyes light up when they grok the concept and its potential. 
The idea that they can create random test data on the fly and pour this into the app step back and see what happens is exciting to people looking to find new blockers on their apps path to reliability.
But it's not long before a cloud appears in their sunny demeanour and they start to conceive of the possible pitfalls. Here are a few tips on how to avert the common apparent blockers. (Part 1) Problem: I've created loads of random numbers as input data, but how will I know the answer the software returns, is correct? - Do I have to re-implement the whole app logic in my test code?
Do you remember going to the fun-fair as a kid? Or maybe you recall taking your kids now as an adult? If so then you no doubt are familiar with the height restriction -…

DevOps and Software Testing.

Most of my recent work has been with DevOps teams. While in one sense DevOps is another evolution in software development. It also introduces some new skill requirements and responsibilities into the daily routine of a tester.


I've created a short video to highlight some of these changes and the opportunities they bring. It's not an exhaustive view of DevOps but it gives a highlight of what you could be working with.


While DevOps isn't a panacea to our software development problems, I have found that empowering teams with the ability to build and use the tools they need, can rapidly improve team morale and productivity.