CSP

A couple of years back as the US presidential campaign was ramping up, the Trump camp did something stupid. I know, we're all shocked but bear with me because it's an important part of the narrative of this post. One of their developers embedded this code in the campaign's donation website: <script src="https://github.com/igorescobar/jQuery-Mask-Plugin/blob/gh-pages/js/jquery.mask.min.js" type="text/javascript></script> See the problem? This tag was in the source code over at secure.donaldjtrump.com/donate-homepage yet it was pulling script directly off Igor Escobar's GitHub repository for the project. Now, imagine if Igor took a dislike to Trump. Or someone else took issue with the bloke...

I've long been a proponent of Content Security Policies (CSPs). I've used them to fix mixed content warnings on this blog after Disqus made a little mistake, you'll see one adorning Have I Been Pwned (HIBP) and I even wrote a dedicated Pluralsight course on browser security headers. I'm a fan (which is why I also recently joined Report URI), and if you're running a website, you should be too. But it's not all roses with CSPs and that's partly due to what browsers will and will not let you do and partly due to what the platforms running our websites will and will not let you do. For example, this blog runs on Ghost Pro which is a managed...

I run a workshop titled Hack Yourself First in which people usually responsible for building web apps get to try their hand at breaking them. As it turns out, breaking websites is a heap of fun (with the obvious caveats) and people really get into the exercises. The first one that starts to push people into territory that's usually unfamiliar to builders is the module on XSS. In that module, we cover reflected XSS which relies on the premise of untrusted data in the request being reflected back in the response. For example, if we take the sample vulnerable site I use in the exercises and search for "foobar", we see the following: You can see the search...

It's finally time: it's time the pendulum swings further towards the "secure by default" end of the scale than what it ever has before. At least insofar as securing web traffic goes because as of this week's Chrome 62's launch, any website with an input box is now doing this when served over an insecure connection: It's not doing it immediately for everyone, but don't worry, it's coming very soon even if it hasn't yet arrived for you personally and it's going to take many people by surprise. It shouldn't though because we've known it's coming for quite a while now starting with Google's announcement back in April. That was then covered pretty extensively by the tech press...

Content security policies (CSPs) can be both a blessing and a curse. A blessing because they can do neat stuff like my recent piece on upgrading insecure requests yet a curse because they can also do screwy things like break your site. Now in fairness, the breaking bit linked to there was more because of Safari's screwy implementation than because of the CSP spec itself, but that brings me to today's post on yet another screwy browser implementation of CSP. This time, it's Chrome's turn and it didn't just cause content to be blocked, it actually cost me money. Let me explain. I have a donate page on Have I been pwned (HIBP). I honestly didn't expect people to give...

I write a blog with a lot of security things on it so understandably, it upsets me somewhat when my site throws security warnings: I'd had a number of people report this and indeed I'd seen it myself, albeit transiently. Diving into the console, I found the source of the problem: Who the hell is Circulate?! And what are they doing in my blog? Let's find out: Right... I don't have any ads on my blog these days (just sponsor messages) so there shouldn't be any third-party monetisation going on. However, what I'd noticed about this issue is that it always seemed to occur when loading Disqus comments and certainly they do some ad things, albeit ad things that I'd...

A couple of months ago I did a video titled Understanding CSRF, the video tutorial edition which was a pretty raw run through of the mechanics and defences of cross site request forgery. It's content I often show in my workshops and I recorded the video pretty much as I present it in those sessions. Today I thought I'd do one on content security policies or as we otherwise know it, CSP. This is a response header that tells the browser a number of things about what it can and can't do once it loads up a website and it's a really neat additional defence against risks such as cross site scripting. When you watch the video, you'll see how...

I’m a big proponent of the content security policy paradigm (CSP) supported by modern browsers. In fact I’m so keen on them I even wrote a Pluralsight course: Introduction to Browser Security Headers. (Sidenote: I’m enormously happy with how well this course has been received, seems there’s an appetite for securing our things after all!) Now if you’re not sure what all the fuss is about, have a quick read of my launch blog post for the course. This gives a pretty good overview of why CSP (among other headers) is awesome. Writing all this content about how the headers work should mean I know what I’m doing...

I’ve been doing this fantastic demo about browser security headers in a lot of my recent talks and workshops. It’s always a lot of fun and it’s very interactive – you can try this out for yourself right now – and it works like this: So cross site scripting (XSS) is still a big thing. Yes it’s been around for ages and yes we should be on top of it by now, but here we are. Anyway, I was at the AppSecEU conference in the Netherlands a few months ago and a local guy called Breno de Winter did a fantastic talk in which he illustrated the prevalence of XSS by showing...