'Serious' security flaws found on official UK tax site

So although they are alright findings (arbitrary url redirect and dom-ish xss) the main take away from the article is that it is WAY too hard to contact anyone from any form of CERT in the UK whatsoever.

I've tried myself to report vulnerabilities[1] and it's nearly impossible to find even the most generic of contact emails. I usually end up passing the info on to friends who do more gov work than myself. There REALLY needs to be a generic cert/security@gov.uk email somewhere.

[1] not going out of my way to find anything, but in the past if i receive a (usually HMRC related) phishing email from a .gov domain, i'll try and dig up a CERT email, or JANET if it is university related.

Here's the direct link to the report: https://medium.com/@Zemnmez/how-to-hack-the-uk-tax-system-i-...

It's a neat write-up - the security folks at Twitch do some great work and this is no exception.

Seems like HMRC really need to work on a responsible disclosure system of some sort, I'm surprised that there are no security@ emails.

I'm also left wondering if Content-Security-Policy could have helped with that XSS.

Let me just share a moment of my personal pain.

In Portugal you fill the taxes in a java application that run in a browser after accepting an invalid security certificate and I always have the feeling that the app as way more access to my computer than it should (saving files is done in a custom interface, not native windows). I'm filled with deep profound sadness and conspiracy theories every single time I have to login to that system.

It is also presented in a web page with a scrollbar and an applet with it's own scrollbars, so it's always a mystery where you'll end up after a mouse scroll.

Oh boy, I used to work at GDS and I met some people from HMRC about their Childcare voucher system thingy. And it used similar techniques to this, I raised it directly with them but they didn't think it was an issue, and my comments were drowned out by a talking shop of technocratic circle jerking.

I can't imagine the motives anyone would want to try and volunteer information about vulnerabilities to the UK gov. Maybe I'm naive, but there's so much hostility towards whitehat researchers that I'd assume Zemnmez is now on some "list" and being monitored/watched/flagged.

What's the reward/risk?

Since when did CSRF and open redirect exploits become serious? Quite common and minor really.

Well, then perhaps it's time to start talk of selling vulnerabilities on the Dark Web to compensate for our time?

It may be brutish, bad, evil, or whatever. Id report willingly for open source or software Ive bought for bug reports or vuln reports. But if I find a serious security issue, I expect to be compensated. And if an org makes it impossible to even contact them, I'll go to their, <ahem> competitors. They do pay.

Perhaps organizations need to be reminded of this.

I once got a parking ticket, and I was trying to figure out how to pay it online. I found a site for the city that I was supposed to put in my license plate number and my date of birth to look up a parking ticket in order to pay it online. I realized that the car was registered to one of my parents, honestly I wasn't sure I had their birthdays exactly memorized, and I couldn't contact both of them at that very moment, so I tried guessing a few dates for the birthday field. I got frustrated, and ... well I've participated in a number of security CTF challenges / puzzle games, where SQL injection is a common technique you're expected to do, and step 1 of many CTF challenges is to literally put the following characters into each text field you find:

    ' OR 'A'='A 

It's like the SQL-injection version of "open sesame". It's generic, fitting a common coding mistake, not tailored to any specific site. It's a force of habit to use while working on CTF challenges ... Desperate to solve my problem of finding my own parking ticket, I reached to that knowledge without really thinking about it and used it. It worked, and the page showed me hundreds of parking tickets with people's full names, license plate and driver license IDs, addresses, and ticket amounts and descriptions. (A glance showed a few people were racking up thousands of dollars of parking tickets, seriously wtf?) I worried about what I did and closed the site. (Well first I scrolled through the list to see if my own parking ticket was there. It wasn't. Turns out where my parking ticket was given was actually in a different city; I was checking the wrong site to begin with.)

I thought about reporting it, but given that I already exploited it and saw private information, I thought twice. I've reported security issues at sites before, but never at a government site or involving me having seen people's private information. I got panicky and just closed the site. I don't owe them the report and the risk it puts me at. It's a nice thing I do for people who invite it or when the risk is low, but somehow I think legal actions are more likely from the site for a local court. If anyone owes anyone, it's the developers for risking people's information so carelessly and for putting me into this type of bind, but somehow I think if I reported this I think I'd be the only one at risk of being treated as a criminal.

I'm not fully sure why I felt compelled to think this was all relevant to this thread. Maybe just to illustrate some of the stress that comes from the vulnerability-reporting side of things. If you want secure systems and for people to report issues as they see them, then sometimes you need to invite the reporters. The difficulty described in the article of even reporting the issue makes me think I'm probably very far from alone in avoiding reporting this type of thing.

Is there a standard way to avoid attacks based on abusing your window.location.replace() calls?

A fun and informative write-up.

I don't think this is a huge step up over a standard phishing attack. A savvy user would notice that the redirected URL doesn't have an EV cert (it might not even have SSL at all). They would probably check the email address the link came from as well.

A non-savvy user would not check the email and would click any link they're sent, redirect, ssl or not. So you might as well send them a standard phishing link.

This means you're targeting users inbetween these two classes, so maybe it's effective for a very specific attack. And if someone is that determined they'll get in no matter what.

Plus 2fa is there on HMRC, if they request a fresh code before any major changes are made it would make it very difficult to do any serious damage.