Where are attachments stored?

There are two different kinds of attachments. One is for tasks and the other one is for events.

Tasks: The attachments are stored in users‘ private iCloud account Events: They are stored in a public iCloud database The reasons behind this implementation are:

In order to make this as easy as possible, attachments are stored in a public database and they will be deleted after 15 days (counting from the start date of the event).

If a user added something to an event which is shared as well others can see it. Thus there is a URL starting with file.staysorted.com to access them.