A misconfigured Amazon Web Services S3 storage bucket exposed sensitive data on consumers' financial histories, contact information, and mortgage ownership.

A major data leak resulting from yet another misconfigured Amazon Web Services S3 storage bucket has exposed sensitive information of 123 million American households. The cloud repository included data from analytics firm Alteryx, reports the UpGuard Cyber Risk Team.

Also exposed were massive data sets belonging to Alteryx partners Experian, the consumer credit reporting agency, and the US Census Bureau. Information from Experian's ConsumerView marketing database and the 2010 US Census were leaked. Home addresses, contact information, financial histories, and analyses of purchasing behavior were publicly available.

UpGuard's director of cyber risk research, Chris Vickery, found the AWS S3 bucket at the subdomain "alteryxdownload" containing sensitive data. The repository was configured to allow any AWS "Authenticated Users" to download its data, meaning anyone with a free Amazon AWS account could access the bucket's information.

"Taken together, this exposed data provide a highly detailed database of tens of millions of Americans' personal, financial, and private lives," UpGuard says. This leak is a "prime example" of how third-party vendor risk can lead to sensitive data exposure.