The following is a description of how Tyler Schmidtke and I obtained free JetCash shortly after the launch of the site. This research was conducted on July 25, 2015. We worked with Jet to ensure that the finding described in this post was remedied prior to this blog post being published.
Jet.com is a recently launched eCommerce site hoping to reinvent online shopping. There has been quite a lot of hype around it, so Tyler and I decided to check it out. In browsing the site and watching some of the videos that had been posted, we learned of JetCash, free credits for jet.com that could be earned by shopping at third party retailers. Jet refers to this as Shop Anywhere. In investigating these credits further, we learned that verification for external purchases relied on submission of order confirmation, from the third party, via email. Jet launched with a large list of external vendors, including Nike.com. What was enticing about Nike.com was that 30 percent of the total purchase price at Nike.com, could be directly converted to JetCash.
Upon seeing the conversion rate and looking at the validation method for external purchases, we decided to create an account to test this third party order validation method. Jet.com utilizes a subscription model; however, considering its recent launch, I was able to find a promo code to get 6 months of access for free. Once the account had been created, I proceeded to make a purchase on Nike.com. I didn’t want to invest too much in testing Jet’s external purchase validation, so Tyler and I decided that we would purchase the cheapest thing available (Nike sweat bands).
Once the order had been placed, we waited to receive the confirmation email. We suspected that this email would be HTML, meaning that it could be easily modified prior to sending to Jet for verification. Shortly after placing the order for 1 Nike sweat band, I received an order confirmation in my inbox. The confirmation email was fairly simple, containing an order number, shipping information, and order details. Considering the validation process relied on this confirmation email, we thought that we would modify the email prior to forwarding it on to the confirmation email at Jet (firstname.lastname@example.org).
We then just simply edited the html and plain text portions of the email to reflect a quantity of 20 sweat bands instead of 1, and updated the prices accordingly. The email that we forwarded then looked like this:
Our purpose for modifying the email was to identify a potential vulnerability in this functionality of Jet.com, so we only modified the email to potentially obtain a slight amount of JetCash. We increased the quantity of the sweat bangs in the confirmation email to 20 and appropriately updated the tax and total. This brought the total of our fabricated order to $114.75, enough to earn us approximately $30 in JetCash.
We sent the modified confirmation email and hoped for the best. After waiting a short while, we received the following email confirming that we had earned $30 in JetCash.
It should be noted that we had no intention of using any of this free JetCash. This test was simply conducted for research, to potentially identify a vulnerability in this feature of Jet.com. We notified Jet of our findings and ultimately received the following response.
– Jet does not consider this a security issue as there was no bug present. The steps you describe highlight a temporary process that would allow people to commit fraud and potentially not be caught.
– In order to not delay the launch of Jet Anywhere, the program was launched with a manual verification step for the first two weeks until a more automated link tracking mechanism was in place. Some merchants had automatic link tracking in place while others were manual.
– Jet was founded on core values of trust, transparency and fairness. Jet trusted the “good” in our members to only forward us legitimate receipts and reward them with instant JetCash, and not intentionally committing fraud by altering an actual order.
– The process is now fully-implemented with click-tracking, merchant verification, and pending jet cash in case someone later cancels their purchase.
As stated in Jet’s response, this issue has been resolved. While this was not necessarily a vulnerability related to the technical aspects of Jet.com, Tyler and I still feel that this finding was a signficant flaw that existed on Jet.com during its initial launch period. During the reporting process, Jet was incredibly responsive, keeping in touch with Tyler and I until the issue had been resolved.
During this process, we also learned that Jet’s official bug bounty program is run through Bug Crowd. If you’re interested in helping Jet out by hunting for bugs, you can learn more about the program here: https://bugcrowd.com/jet