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Vulnerability in Moonpig API Exposed Customer Data: Researcher

Online personalized card and gift company Moonpig has shut down its mobile applications after a researcher revealed the existence of a serious vulnerability that could have been leveraged to gain access to customer information.

Moonpig, a PhotoBox Group company, is the largest personalized greeting cards maker in the United Kingdom. The company has a total of 3.6 million active customers in the UK, the US, and Australia.

According to developer Paul Price, the API used by the company’s mobile apps relied on a flawed authentication mechanism that allowed malicious hackers to easily harvest customer details.

The expert discovered a direct object reference vulnerability after analyzing the requests sent to the server when users log in to their accounts from the Moonpig application for Android. Instead of relying on a username and password for authentication, the requests contained static credentials, and the only identifiable piece of information was a customer ID. By changing the value of this ID, the researcher managed to access information from other accounts.

The Moonpig API supports OAuth 2.0 authorization which, according to Price, would address the issue, but the feature is not implemented in the Android client.

A description for all the API methods is available on a help page, making it easy for an attacker to abuse them in order to gain access to the information he’s after. The “GetCreditCardDetails” method, for example, could be used to retrieve any customer’s name, card type, card expiry date, and the last four digits of the card number.

“An attacker could easily place orders on other customers accounts, add/retrieve card information, view saved addresses, view orders and much more,” Price said in a blog post.

“I hit my test users a few hundred times in quick succession and I was not rate limited. Given that customer IDs are sequential an attacker would find it very easy to build up a database of Moonpig customers along with their addresses and card details in a few hours - very scary indeed,” the researcher noted.

Price said he first notified the company in August 2013. In September 2014, he contacted Moonpig again and he was told that the issue would be addressed before Christmas. The researcher said he wanted to give the company the chance to fix the vulnerability, but after seeing that no measures had been taken for approximately 17 months, he decided to make his findings public in order to force Moonpig to address the flaw.

“We are aware of the claims made this morning regarding the security of customer data within our Apps. We can assure our customers that all password and payment information is and has always been safe,” Moonpig representatives told SecurityWeek. “The security of your shopping experience at Moonpig is extremely important to us and we are investigating the detail behind today’s report as a priority. As a precaution, our Apps will be unavailable for a time whilst we conduct these investigations and we will work to resume a normal service as soon as possible. The desktop and mobile websites are unaffected.”

Moonpig is not the only UK organization whose services have been found to be affected by such a vulnerability. On Monday, IT security consultant Paul Moore reported identifying a similar issue on Immobilise, the UK’s National Property Register website. In the case of Immobilise, attackers could have harvested more than 28 million records.

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Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.