Flaw in Fiserv banking platform exposed personal data

The exploit, which has now been patched, affected customers banking with hundreds of financial institutions

US-based financial services firm Fiserv has just fixed a flaw in its web platform that exposed the personal and financial details of a vast number of banking customers.

With more than 12,000 clients across the world using the company's services, it is hard to establish how many customers' details were exposed in the 'information disclosure vulnerability' found by security researcher Kristian Erik Hermansen.

Advertisement - Article continues below

When logging into his local bank, which uses Fiserv's platform, Hermansen learned email alerts for financial transactions were assigned an 'event number', which he successfully predicted were distributed in sequence, according to KrebsOnSecurity.

Using this knowledge, the researcher was able to directly view alerts set up by another customer by rewriting the site's code in his browser and sending a request for an altered event number. He was able to view the customer's email address, phone number and bank account number - as well as view and edit alerts they had previously set up.

"I shouldn't be able to see this data," he said. "Anytime you spend money that should be a private transaction between you and your bank, not available for everyone else to see." He added a criminal could have exploited the flaw to steal information from customers.

Together with KrebsOnSeceurity author Brian Krebs, Hermansen worked to verify whether or not the flaw was exclusive to his own bank's installation of the platform. They soon discovered hundreds of other Fiserv-affiliated banks may have been just as vulnerable as those they had tested.

Advertisement - Article continues below
Advertisement - Article continues below

IT Pro approached Fiserv for comment, and to establish how many institutions in the UK may have been affected, if any, but the company did not respond at the time of writing. A spokesperson told Krebs that Fiserv had responded accordingly, and corrected the issue.

"After receiving your email, we promptly engaged appropriate resources and worked around the clock to research and remediate the situation," the spokesperson said.

"We developed a security patch within 24 hours of receiving notification and deployed the patch to clients that utilise a hosted version of the solution. We will be deploying the patch this evening to clients that utilise an in-house version of the solution."

While information disclosure vulnerabilities are among the most common types of website security issues, according to Krebs, they are also the most preventable and easy to fix. But they can also cause just as much damage to a company's brand as more severe security risks.

Featured Resources

Successful digital transformations are future ready - now

Research findings identify key ingredients to complete your transformation journey

Download now

Cyber security for accountants

3 ways to protect yourself and your clients online

Download now

The future of database administrators in the era of the autonomous database

Autonomous databases are here. So who needs database administrators anymore?

Download now

The IT expert’s guide to AI and content management

Your guide to the biggest opportunities for IT teams when it comes to AI and content management

Download now


cyber security

Zoom hires ex-Facebook CSO Alex Stamos to boost platform security

8 Apr 2020

HP Support Assistant flaws leave Windows devices open to attack

6 Apr 2020
cyber security

Safari bug let hackers access cameras on iPhones and Macs

6 Apr 2020
video conferencing

Zoom CEO admits company "moved too fast" as privacy issues mount

6 Apr 2020

Most Popular

Mobile Phones

Microsoft patents a mobile device with a third screen

6 Apr 2020
application programming interface (API)

Apple buys Dark Sky weather app and leaves Android users in the cold

1 Apr 2020

A critical flaw in 350,000 Microsoft Exchange remains unpatched

7 Apr 2020