Facebook design flaw let thousands of kids join chats with unauthorized users

Facebook’s Messenger Kids app is built around a simple premise: children shouldn’t be able to talk to users who haven’t been approved by their parents. But a design flaw allowed users to sidestep that protection through the group chat system, allowing children to enter group chats with unapproved strangers.

For the past week, Facebook has been quietly closing down those group chats and alerting users, but has not made any public statements disclosing the issue. The alert, which was obtained by The Verge, reads as follows:

Hi [PARENT], 
We found a technical error that allowed [CHILD]’s friend [FRIEND] to create a group chat with [CHILD] and one or more of [FRIEND]’s parent-approved friends. We want you to know that we’ve turned off this group chat and are making sure that group chats like this won’t be allowed in the future. If you have questions about Messenger Kids and online safety, please visit our Help Center and Messenger Kids parental controls. We’d also appreciate your feedback.

Facebook confirmed to The Verge that the message was authentic, and said the alert had been sent to thousands of users in recent days. “We recently notified some parents of Messenger Kids account users about a technical error that we detected affecting a small number of group chats,” a Facebook representative said. “We turned off the affected chats and provided parents with additional resources on Messenger Kids and online safety.”..

https://www.theverge.com/2019/7/22/20706250/facebook-messenger-kids-bug-chat-app-unauthorized-adults