An apparent flaw that lets users add any amount of money onto already processed PayPal transactions is a feature, not a bug, according to the payments giant.
The function was designed to allow sellers to add additional costs for services like shipping on the top of transaction totals which customers had approved through the PayPal website.
Sellers would be expected to add small amounts but TU-Berlin IT student Jan Kechel found PayPal had not limited the amount of cash that could be swindled and sent the company a proof of concept script.
"In PayPal Express Checkout the online shop can transfer any amount, no matter which amount the client actual confirmed at the PayPal website," Kechel said.
"This proof of concept transfers only one Euro more than the confirmed amount, but I also tried with 200 Euros and it works just the same."
PayPal told Vulture South Kechel's bug was more of a shiny button.
"We can confirm that through our Bug Bounty Program a researcher reported a suspected vulnerability with our PayPal Express Checkout," a spokesperson said.
"After looking into the issue, we communicated this is not in fact a vulnerability. We work closely with our merchants who use Express Checkout to provide them the flexibility they need to complete their transactions in a timely manner so they can offer excellent payments experiences to their customers."
The company did not say if it plans to cap the rate or otherwise reduce the potential impact of the fraud. Defrauded customers do have the option of seeking reimbursements from PayPal, which like many banks shells out for fraudulent transactions in the name of consumer confidence.
Customers would be alerted to the scam if they opted for email verification and further bothered to open them as the payment details were contained in the body of the messages.
Last month, former NASA hacker turned white hat Razvan Cernaianu, aka Tinkode, reported a flaw to PayPal's bug bounty team which he said allowed fraudsters to double their money.
The payment giant brushed off the report but did not say how it could prevent one off instances of the scam which involved the funneling of cash to a mule account prior to a dispute claim being lodged. ®