BigBlueButton is an open-source virtual classroom. A denial-of-service (DoS) vulnerability in versions prior to 3.0.13 allows any authenticated user to crash the chat functionality for all participants in a meeting by sending a malformed reactionEmojiId in the GraphQL mutation chatSendMessageReaction. Version 3.0.13 contains a patch. No known workarounds are available.
The product does not properly anticipate or handle exceptional conditions that rarely occur during normal operation of the product.