Recently, I reported a security issue in the new Firefox Screenshots feature (fixed in Firefox 56). This issue is remarkable for a number of reasons. First of all, the vulnerable code was running within the Web Extensions sandbox, meaning that it didn’t have full privileges like regular Firefox code. This code was also well-designed, with security aspects taken into consideration. In fact, what I found were multiple minor flaws, each of them pretty harmless. And yet, in combination these flaws were sufficient for Mozilla to assign security impact “high” to my bug report (only barely, but still). Finally, I think that these flaws only existed due to shortcomings of the Web Extensions platform, something that should be a concern given that most extensions based on it are not well-designed.

I’ve been increasingly using Bugcrowd lately, a platform that manages security bug bounty programs for its clients and allows security researchers to contribute to a number of such programs easily. Previously, I’ve mostly reported security issues in Mozilla and Google products. Both companies manage their bug bounty programs themselves and are very invested in security, so Bugcrowd came as a considerable culture shock.

First of all, it appears that many companies consider bug bounty programs an alternative to building solid in-house security expertise. They will patch whatever bugs are reported, but they don’t seem to draw any conclusions about the deficiencies in their security architecture. Eventually, even the most insecure application will have enough patches applied that finding new issues takes too much effort for the monetary rewards offered. At that point, almost no new reports will be coming in and for the management it’s “mission accomplished” I guess. Sadly, with security being an afterthought the product remains inherently insecure, even the smallest change could potentially open new security holes.

Almost exactly a year ago I wrote a blog post explaining how permission prompts are a particularly problematic area for a functioning extension ecosystem. While at this point it was already clear that Firefox would show some kind of permission prompt, I hoped that Mozilla would put more thought into it than Chrome did. Unfortunately, this didn’t quite happen. In fact, as I now experienced, the permission prompt in Firefox turned out significantly worse than the one in Chrome.

I’ve finally released Easy Passwords as a Web Extension (not yet through AMO review at the time of writing), so that it can continue working after Firefox 57. To be precise, this is an intermediate step, a hybrid extension meant to migrate data out of the Add-on SDK into the Web Extension part. But all the functionality is in the Web Extension part already, and the data migration part is tiny. Why did it take me so long? After all, Easy Passwords was created when Mozilla’s Web Extensions plan was already announced. So I was designing the extension with Web Extensions in mind, which is why it could be converted without any functionality changes now. Also, Easy Passwords has been available for Chrome for a while already.

Emscripten allows compiling C++ code to JavaScript. It is an interesting approach allowing porting large applications (games) and libraries (crypto) to the web relatively easily. It also promises better performance and memory usage for some scenarios (something we are currently looking into for Adblock Plus core). These beneficial effects largely stem from the fact that the “memory” Emscripten-compiled applications work with is a large uniform typed array. The side-effect is that buffer overflows, use-after-free bugs and similar memory corruption mistakes are introduced to JavaScript that was previously safe from them. But are these really security-relevant?

This announcement by the Princeton University is making its rounds in the media right now. What the media seems to be most interested in is their promise of ad blocking that websites cannot possibly detect, because the website can only access a fake copy of the page structures where all ads appear to be visible. The browser on the other hand would work with the real page structures where ads are hidden. This isn’t something the Princeton researchers implemented yet, but they could have, right?

Six month ago I wrote a detailed analysis of LastPass security architecture. In particular, I wrote:

So much for the general architecture, it has its weak spots but all in all it is pretty solid and your passwords are unlikely to be compromised at this level. However, as described in my blog post the browser integration turned out to be a massive weakness. The LastPass extension on your computer works with decrypted data, so it needs to be extra careful – and at the moment it isn’t.

I went on to point out Auto Fill functionality and internal messaging as the main weak spots of the Last Pass browser extensions. And what do I read in the news today? Google reporter Tavis Ormandy found two security vulnerabilities in LastPass. In which areas? Well, Auto Fill and internal messaging of course.

As I mentioned previously, an efficient PBKDF2 implementation is absolutely essential for Easy Passwords in order to generate passwords securely. So when I looked into Microsoft Edge and discovered that it chose to implement WebCrypto API but not the PBKDF2 algorithm this was quite a show-stopper. I still decided to investigate the alternatives, out of interest.

My latest news validation adventure started because my wife overheard a show on Russian TV explaining the “real” reasons behind the Syrian civil war. The argument appeared to be balanced by explaining how various foreign forces have a hidden agenda in the conflict — including Russia which needs to prevent the Quatar-Turkey pipeline from happening. And what’s in for US? According to that show, vast amounts of oil were discovered in Syria and the US were looking for ways to exploit those. Such an easy and simple explanation for a very complex conflict seemed suspicious and so I decided to look into it.

With Easy Passwords I develop a product which could be considered a Last Pass competitor. In this particular case however, my interest was sparked by the reports of two Last Pass security vulnerabilities (1, 2) which were published recently. It’s a fascinating case study given that Last Pass is considered security software and as such should be hardened against attacks.

I decided to dig into Last Pass 4.1.21 (latest version for Firefox at that point) in order to see what their developer team did wrong. The reported issues sounded like there might be structural problems behind them. The first surprise was the way Last Pass is made available to users however: on Addons.Mozilla.Org you only get the outdated Last Pass 3 as the stable version, the current Last Pass 4 is offered on the development channel and Last Pass actively encourages users to switch to the development channel.