When I got home from an out-of-town trip yesterday, there was a letter from IKEA containing a welcome letter and my member card. The first thing that caught my eye was the third line in the welcome letter: "Your login password: Your date of Birth (DDMMYYYY)". My WHAT? That doesn't seem very secure, does it?
I opened up my browser and went to their site to have a closer look. Right on the login page was a password reminder link, which I clicked. That opened up a message box confirming that they do indeed use your date of birth as a password, but even worse: the wording of that password reminder even suggests that you can't even change your password later. After logging in I couldn't find a way to change the password or DOB, so I think you're stuck with your DOB as the password for your "IKEA family" account...
What's wrong with using your date of birth as a password?
Why is this bad, you say? Not everyone knows my date of birth, right? Well, unfortunately, it is very easy for a computer to test all possible combinations of someone's date of birth and make automated requests to login pages like the one used by "IKEA family". There are after all only 36525 possible date combinations in a 100 year timespan. If we assume that most "IKEA family" members are between 17 and 85 years old, that drops to 24837 combinations. That is way to easy to bypass, and in a real-world attack each member account would (on average) require about half as many attempts before the correct DOB is found: just 12k requests per member account. This can be done in a very short timespan (seconds) by your average home computer or smartphone.
Now, someone may argue that this is the password for a membership account with a 16-digit membership number, a membership number which would be hard for someone else to guess. That may be the case, it looks to me like the membership number starts with a 999320 prefix, followed by zeroes, and then a 6-digit membership number. Based on how the number is formatted, I would guess is that those membership numbers are issued in sequential order, which would make it easy to automate a brute-force attack. An attacker could start at 9993 2000 0010 0000 and work his/her way up through the account list.
An automated brute-force attack would probably need to make somewhere between 5-8 billion requests to the "IKEA family" site to retrieve all members' data. This may sound like a lot, but for a computer it is not very hard work at all to make a few billion http roundtrips over the span of a few days...
As an added bonus: the entire site, including the login page, use plaintext http instead of https. Whenever you access a http-only site from an open wifi-connection or a compromized network you are sharing your information with whoever may be listening in.
What's at risk?
IKEA family is just a loyalty program, where you can collect bonus points and get discounts on items in their stores. Fortunately, there doesn't seem to be a way to tie a credit card or bank account to it [yet], [in this country].
What is the risk if someone compromise an IKEA family member account? PII: Personally Identifiable Information. When you sign up for an IKEA family membership, they ask for your name, address, email, DOB, ID card or passport number, mobile phone number, family details etc. I shared that information with IKEA, but I may not necessarily want to share it with a hacker in China, or Russia, or elsewhere. Likewise, IKEA may not want to share their customer data with hackers who may use it for phishing, or even resell it to competitors.
I immediately updated my profile and changed name/address/etc to dummy data, and I will email IKEA in a short while and ask them to delete my "IKEA family" account until they handle my (and other members') information in a more responsible way. Maybe I will even join "IKEA family" again in the future, if they become more responsible with how they handle member data.
In addition to accessing your PII, the site also allow you to redeem bonus points and to review transaction history (including previous purchases at IKEA stores).
I had a quick look at the login pages for "IKEA family" sites in other countries, and it looks like the IKEA family program's website is implemented differently in different countries. The IKEA family sites in nearby Singapore and Malaysia appear to be identical to the one used by IKEA Thailand, while the one used by IKEA Sweden appear to be a bit more secure.
Dear IKEA, ...
If anyone from IKEA happens to come across this, please have a look at how the online version of your "IKEA family" loyalty site is implemented in some countries. You are making your membership data easily accessible to hackers and (potential) evil-minded competitors.
If whoever built the "IKEA family" site is this sloppy with passwords, there may of course be other weaknesses as well. If you change the way you handle authentication, you may also want to spend a bit of time on looking into other security aspects of your site.
To everyone else: your date of birth is not a good password. Neither is your grandmother's date of birth, your dog's maiden name, or "p@ssw0rd69". Don't do it, especially if you are using it to protect other people's PII. If a site you are using insist on using a weak/bad password, reconsider if you really want/need to use that site and limit what information you share with it.