How Edge Follows In IE’s Security Failings

I’ve generally been pretty defensive of Microsoft Edge, the default web browser in Windows 10. Unlike its much-mocked predecessor Internet Explorer, Edge is fast, clean, modern, and boasts good standards-compliance: all of the things that Internet Explorer infamously failed at! I was genuinely surprised to see Edge fail to gain a significant market share in its first few years: it seemed to me that everyday Windows users installed other browsers (mostly Chrome, which is causing its own problems) specifically because Internet Explorer was so terrible, and that once their default browser was replaced with something moderately-good this would no longer be the case. But that’s not what’s happened. Maybe it’s because Edge’s branding is too-remiscient of its terrible predecessor or maybe just because Windows users have grown culturally-used to the idea that the first thing they should do on a new PC is download a different browser, but whatever the reason, Edge is neglected. And for the most part, I’ve argued, that’s a shame.

Edge's minimalistic Certificate View.
I ranted at an Edge developer I met at a conference, once, about Edge’s weak TLS debugging tools that couldn’t identify an OCSP stapling issue that only affected Edge, but I thought that was the worse of its bugs… until now…

But I’ve changed my tune this week after doing some research that demonstrates that a long-standing security issue of Internet Explorer is alive and well in Edge. This particular issue, billed as a “feature” by Microsoft, is deliberately absent from virtually every other web browser.

About 5 years ago, Steve Gibson observed a special feature of EV (Extended Validation) SSL certificates used on HTTPS websites: that their extra-special “green bar”/company name feature only appears if the root CA (certificate authority) is among the browser’s default trust store for EV certificate signing. That’s a pretty-cool feature! It means that if you’re on a website where you’d expect to see a “green bar”, like Three Rings, PayPal, or HSBC, then if you don’t see the green bar one day it most-likely means that your connection is being intercepted in the kind of way I described earlier this year, and everything you see or send including passwords and credit card numbers could be at risk. This could be malicious software (or nonmalicious software: some antivirus software breaks EV certificates!) or it could be your friendly local network admin’s middlebox (you trust your IT team, right?), but either way: at least you have a chance of noticing, right?

Firefox address bars showing EV certificates of Three Rings CIC (GB), PayPal, Inc. (US), and HSBC Holdings plc (GB)
Firefox, like most browsers, shows the company name in the address bar when valid EV certificates are presented, and hides it when the validity of that certificate is put into question by e.g. network sniffing tools set up by your IT department.

Browsers requiring that the EV certificate be signed by a one of a trusted list of CAs and not allowing that list to be manipulated (short of recompiling the browser from scratch) is a great feature that – were it properly publicised and supported by good user interface design, which it isn’t – would go a long way to protecting web users from unwanted surveillance by network administrators working for their employers, Internet service providers, and governments. Great! Except Internet Explorer went and fucked it up. As Gibson reported, not only does Internet Explorer ignore the rule of not allowing administrators to override the contents of the trusted list but Microsoft even provides a tool to help them do it!

Address bars from major browsers connecting to a spoofed site, with EV certificate "green bars" showing only in Internet Explorer and Edge.
From top to bottom: Internet Explorer 11, Edge 17, Firefox 61, Chrome 68. Only Internet Explorer and Edge show the (illegitimate) certificate for “Barclays PLC”. Sorry, Barclays; I had to spoof somebody.

I decided to replicate Gibson’s experiment to confirm his results with today’s browsers: I was also interested to see whether Edge had resolved this problem in Internet Explorer. My full code and configuration can be found here. As is doubtless clear from the title of this post and the screenshot above, Edge failed the test: it exhibits exactly the same troubling behaviour as Internet Explorer.

Thanks, Microsoft.

Safari doesn't fall for it, either.
I also tried Safari (both on MacOS, above, and iOS, below) and it behaved as the other non-Microsoft browsers do (i.e. arguably more-correctly than IE or Edge).

I shan’t for a moment pretend that our current certification model isn’t without it’s problems – it’s deeply flawed; more on that in a future post – but that doesn’t give anybody an excuse to get away with making it worse. When it became apparent that Internet Explorer was affected by the “feature” described above, we all collectively rolled our eyes because we didn’t expect better of everybody’s least-favourite web browser. But for Edge to inherit this deliberate-fault, despite every other browser (even those that share its certificate store) going in the opposite direction, is just insulting.

The Latest Stupidity From The Internet Explorer Team

Have you seen the latest stupidity that the Windows Internet Explorer team have come up with? Ten Grand Is Buried Here.

The idea is that they encourage you to give up whatever browser you’re using (assuming it’s not Internet Explorer 8), calling it names (like “old Firefox” if you’re using Firefox, “boring Safari” if you’re using Safari, “tarnished Chrome” if you’re using Chrome, and… “that browser” if you’re using Opera) and upgrade to Internet Explorer 8, and they’ll be giving out clues on their Twitter feed about some secret website that’ll only work in IE8 at which you can register and win $10,000AUS (yes, this is an Australian competition).

After looking at the site in Firefox, Safari, Chrome, and Opera, I thought I’d give it a go in Internet Explorer 8. But it didn’t work – it mis-detected my installation of IE8 as being IE7 (no, I didn’t have Compatability Mode on).

In the end, though, I just used User Agent Switcher to make my copy of Firefox pretend to be Internet Explorer 8. Then it worked. So basically, all that I’ve learned is that Firefox does a better job of everything that Internet Explorer does, including viewing websites designed to only work in Internet Explorer. Good work, Microsoft. Have a slow clap.

The Right To Read

[this post was lost during a server failure on Sunday 11th July 2004; it was partially recovered on 21st March 2012]

If you haven’t already read it, take a look at The Right To Read, a very short story written in 1997 and updated in 2002 – it’ll only take you a few minutes to read; it’s not ‘techie’ (anybody would understand it!), and it is relevant. The kind of things that are expressed in the story – while futuristic (and facist) sounding now, are being put into effect… slowly, quietly… by companies such as Sony, Phillips, Apple, and Microsoft: not to mention the manufactors of CDs and DVDs.

It’s been circulating the ‘net for years, but recent events such as InterTrust’s Universal Digital Rights Management System (report: The Register), which they claim will be ready within 6 months, and Microsoft’s ongoing work on the ‘Palladium’ project (report: BBC News) – topical events which mark the beginning of what could be the most important thing ever to happen in the history of copyright law, computing, and freedom of information.

So, go on – go read… [the remainder of this post, and three comments, have been lost]