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 freeze or crash the entire server by abusing the polling features Choices
response type. By submitting a malicious payload with a massive array in the answerIds
field, the attacker can cause the current meeting — and potentially all meetings on the server — to become unresponsive. 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.