We’re all familiar with CAPTCHA right? That impenetrable fortress of crazy squiggly characters that only a real human can decipher. Whilst they tend to drive us a bit nuts, they do actually provide a valuable function in that they prevent the automation of requests against online services. For example, you can’t get yourself a Google account [https://accounts.google.com/SignUp?continue=http%3A%2F%2Fwww.google.com.au%2F&hl=en] without first wrapping your head around what on earth this one says:...

Another week, another major security incident with a significant website. So the news this time is that Zappos – those guys who sell shoes (among other things) – to folks in the US may have, uh, accidentally disclosed somewhere in the order of 24 million user accounts [http://www.pcworld.com/businesscenter/article/248244/zappos_hacked_what_you_need_to_know.html] . Bugger. Now of course at the root of this is inevitably yet more evildoers intent on breaking through website security for financial...

I love ELMAH [http://code.google.com/p/elmah/] – this is one those libraries which is both beautiful in its simplicity yet powerful in what it allows you to do. Combine the power of ELMAH with the convenience of NuGet and you can be up and running with absolutely invaluable error logging and handling in literally a couple of minutes. Yet, as the old adage goes, with great power comes great responsibility and if you’re not responsible with how you implement ELMAH, you’re also only a couple of mi...

Back in September last year we saw the emergence of the padding oracle vulnerability [https://www.troyhunt.com/2010/09/fear-uncertainty-and-and-padding-oracle.html] which suddenly got a whole lot of ASP.NET developers very nervous. The real concern with this vulnerability was that there really wasn’t much you could do at the code level beyond a couple of little tweaks – what was really needed was for patches to get installed on servers and fast. The problem back then was that, well, you couldn’...

Just when you start thinking we’ve seen out the last of the major security breaches for 2011, Christmas day brings us one final whopper for the year: Stratfor [http://en.wikipedia.org/wiki/Stratfor]. Much has already been said about why they might have been hacked and who might [http://www.security-ray.com/2011/12/white-hat-security-firm-stratfor-hacked.html] (or might not [http://pastebin.com/8yrwyNkt]) have done it, but the fact remains that there are now tens of thousands of customer passwo...

This entire series is now available as a Pluralsight course! [http://pluralsight.com/training/Courses/TableOfContents/owasp-top10-aspdotnet-application-security-risks] Writing this series [https://www.troyhunt.com/2010/05/owasp-top-10-for-net-developers-part-1.html] was an epic adventure in all senses of the word: Duration – 19 months to complete a blog series, for crying out loud! Content – approaching 50,000 words, not including all the discussion in comments. Effort – some of the posts, su...

This content is now available in the Pluralsight course "OWASP Top 10 Web Application Security Risks for ASP.NET" [http://www.pluralsight.com/courses/owasp-top10-aspdotnet-application-security-risks] In the final part of this series we’ll look at the risk of an unvalidated redirect or forward. As this is the last risk in the Top 10, it’s also the lowest risk. Whilst by no means innocuous, the OWASP Risk Rating Methodology [https://www.owasp.org/index.php/OWASP_Risk_Rating_Methodology] has determ...

I’ve had a lot of conversations with folks recently about web app performance. Often these conversations have been around the assertion that a content distribution network (here forth referred to as a CDN), is something you need to deploy early on in the optimisation process of a website. Personally, I see a CDN as a last resort; it’s what you turn to when all other performance tuning alternatives have been exhausted and you need to eke out that last little bit of latency by moving the content c...

Websites get hacked. Lots. This year alone we’re looking at some absolute whoppers; Sony, EVE Online, Sony, pron.com, Sony, MySQL.com, did I mention Sony? Many times, the gateway to successful website exploits is simple misconfiguration. Custom errors were left off and thus leaked internal code. Or request validation was turned off which opened up an XSS flaw. These risks are often then leveraged to do other nasty stuff. The thing is, many of these are also easily remotely detectable – certain...

This content is now available in the Pluralsight course "OWASP Top 10 Web Application Security Risks for ASP.NET" [http://www.pluralsight.com/courses/owasp-top10-aspdotnet-application-security-risks] When it comes to website security, the most ubiquitous indication that the site is “secure” is the presence of transport layer protection. The assurance provided by the site differs between browsers, but the message is always the same; you know who you’re talking to, you know your communication is e...