Event management company EventBuilder exposed files containing the personal information of at least 100,000 users who registered for events on its platform.
The data leak was discovered by researcher Bob Diachenko and Clario, a company that provides consumer security and privacy products. The exposed files were found using Grayhat Warfare, a search engine for public buckets.
Diachenko and Clario identified an unprotected Microsoft Azure Blob storage containing thousands of large CSV and JSON files. These files stored more than a million records, including ones containing the personal details of at least 100,000 event registrants.
“The storage in question was supposed to be partially public, to host recorded sessions for link-only access. However, for some reason, the webinar organizers were putting registrant information into the blob,” Clario explained in a blog post. “This meant it was open to indexing by a Public Bucket searcher (Grayhat Warfare), thus compromising their personal information and potentially putting them in danger of being targeted by hackers from across the globe.”
The exposed information included full name, email address, company name, role within the company, phone numbers, and information from the questionnaires answered by users.
EventBuilder is a widely used event management platform that is designed for Microsoft Teams and other Microsoft products. The company says its platform is used to produce more than 1,000 virtual events every month.
The data exposure was discovered on June 10 and it was immediately reported to EventBuilder, which at some point addressed the issue.
SecurityWeek has reached out to EventBuilder for comment and will update this article if the company responds.