CUNY Academic Commons

I just tried to include some .ics file attachments to a forum post to distribute meeting calendar items to the Commons team, and after I pressed submit I was told that they were disallowed for security reasons. I then tried to post them to the Library instead but it wouldn't allow me to select that type of file on my computer.

Is there a specific security risk for uploaded .ics files? If so I'm happy to work around this, but I wasn't sure if they were just part of a blanket blocking and we'd never examined them specifically.