Saturday, December 07, 2013

Security breach at Myntra.com exposes customer's personal information, order history and more

Update (added on 3 Dec 2013): Based on my feedback Myntra.com has now setup security@myntra.com for reporting security issues. Kudos to them for taking the first step towards a better responsible disclosure process and setting an example for other Indian companies.

Last week a bug on Myntra.com let anyone with an account take over random customer accounts and highlighted the lack of responsible disclosure processes among Indian companies.

On 28th November (2013), Myntra.com held a 3-hour (8-11pm) invite only Winter Sale event where a few select customers got an additional 31% off on all orders above a certain amount.

I was one of those customers and decide to login to my Myntra account to see the coupon, except I had forgotten my Myntra account password. So I went ahead and put in my email address and clicked on the forgot password link. As expected I got an email with instructions, to click on a link to set a new password. What happened next was very scary.




I clicked on the link and landed on the page on Myntra.com to set a new password but instead of my email address I saw someone else's email address pre-filled in the form. Curious to see what would happen, I went ahead and put in a new password and lo and behold, Myntra.com had let me take over another customer's account. 




To see if this was repeatable, I went through the forgot password flow again and just like before it had another random customer's email address pre-filled in the form and let me take over that customer's account.




HOLY SHIT. Myntra.com just let me take over two customer accounts. No fancy hacks, just a scary little bug that presented other Myntra customer accounts to me on a platter.

So the first thing I did was see if I could find anything on Myntra.com about responsible disclosure or a security contact but found nothing. So I sent an email to security@myntra.com and it promptly bounced with the message "The email account that you tried to reach is over quota".

Next I got in touch with them on Twitter and 13 hours later someone got in touch with me, 16 hours later I was speaking to a Tech Lead from Myntra.com and 9 days later I have confirmation from them that they have fixed the bug and put measures into place to ensure this doesn't happen again.

Note (added on 8 Dec 2013): The bug was fixed on the same day I reported it and the 9 days mentioned above includes time they took to monitor the fix and the Tech Lead at Myntra.com and me having issues around coordinating the final confirmation phone call.

I don't know how long this bug was live and how many customers accounts were affected but if your account was one of the affected ones, it means someone had COMPLETE access to your account, your personal details like your address and phone number, your order history, your myntra credit points, your saved payment details, your wishlist and your shopping cart.

Apart from the privacy concerns, the biggest threat that you need to protect yourself from, with a security breach like this is that it opens you up to Social Engineering Attacks where anyone with this privileged information can pretend to be from Myntra.com and use it for malicious purposes.

While a lot of people reading this will focus on Myntra, I think it's important to focus on what this incident can teach us about the lack of Responsible Disclosure processes among Indian companies.

If you run an online service (and especially an ecommerce one) you MUST have a responsible disclosure process in place. The Open Web Application Security Project (OWASP) has a good primer on managing your security issue disclosure process. At a very basic level you should atleast have a security@ email address configured. Having a dedicated page for responsible disclosure on your website is an added bonus.

Here are some examples of good responsible disclosure pages to get you started:



Lastly, I think it's important for companies to be transparent and honest about security/data breaches. Hiding details about breaches from your customers makes them vulnerable to all kinds of attacks. Security/Data breaches happen all the time. The only way customers can protect themselves is by being informed.

5 comments:

Sanjeev Kumar Mishra said...

Good catch!! however, looks like a very silly bug in piking the correct email address!! :D maybe some, someone wrote and pushed the code after a DARU party :D

vijay kumar said...

yes, It is really a dangerous one as the details of the person whose account has been hacked have gone into other hands and we never know how that person is, may be he or she misuses your account which can take you in trouble.

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maaz said...

on may 5th
They was a seasonal coupon 'shop30' , by mistake instead of 3 in '30' i pressed 8 & guess what i got 80% OFF that time.
enjoyed it

sumitkumarvishway said...

Hello sandeep did you receive any amount from myntra to identified this bug?

Thanks
Sumit Vishway