Sennheiser exposed personal data of 28,000 customers with leaky S3 bucket

Three Sennheiser headsets stacked on top of each other on a wooden table

Audio equipment manufacturer Sennheiser exposed personal data belonging to around 28,000 customers through a misconfigured Amazon Web Services S3 bucket, researchers revealed on Thursday.

The data in question had been collected between 2015 and 2018 and then stored on a public-facing S3 bucket that has remained dormant ever since, according to experts at VPN reviews website vpnMentor.

The data included customers' full names, email addresses, phone numbers, and home addresses, as well as the names of companies requesting hardware samples and the number of employees they had. At least 407,000 files, totaling 55Gb of data, were available.

"Sennheiser failed to implement any security measures on its S3 bucket, leaving the contents totally exposed and easily accessible to anyone with a web browser and technical skills," the researchers said.


The secure cloud configuration imperative

The central role of cloud security posture management


The researchers discovered the exposed data on October 26, notifying Sennheiser two days later. Following a request for more information on November 1, the researchers sent the company the URL leading to the unsecured server along with examples of the types of information they had been able to lift. The company then locked the server down a few hours later.

VpnMentor said that if anyone had accessed the exposed data, they could have used it for identity theft, enabling them to perpetrate tax, insurance, mortgage, and credit card fraud. They could also have sent phishing emails to victims impersonating Sennheiser in order to source an even greater trove of personal information.

S3 is the storage layer supporting AWS services, and can be configured to be accessible from the public internet or to be private. However, it remains up to customers to make sure the buckets are configured correctly.

Exposing data in misconfigured S3 buckets is a common problem for AWS customers. In August, consumer ratings and review website SeniorAdvisor exposed over three million US senior's personal data via the cloud-based service. In June 2020, vpnMentor also discovered sensitive files from at least 100,000 users across multiple dating sites in exposed S3 storage.

Amazon has attempted to mitigate the problem, which typically stems from human error, with a tool to spot misconfigured resources.

Danny Bradbury

Danny Bradbury has been a print journalist specialising in technology since 1989 and a freelance writer since 1994. He has written for national publications on both sides of the Atlantic and has won awards for his investigative cybersecurity journalism work and his arts and culture writing. 

Danny writes about many different technology issues for audiences ranging from consumers through to software developers and CIOs. He also ghostwrites articles for many C-suite business executives in the technology sector and has worked as a presenter for multiple webinars and podcasts.