Security researcher Avinash Jain discovered more than 8,000 Google Calendars exposed online, that were indexed by the Google search engine.
The issue isn’t new, however users may not be aware of it. It occurs when users make the Google calendar public.
“While this is an intended setting by the user and intended behavior of the service,” Jain says, “the main issue here is that anyone can view any public calendar by making a single Google search query, and without the calendar link being shared with them.”
Users should review their calendar sharing options – see https://support.google.com/a/answer/60765?hl=en.
Read more about it here.