BigBlueButton is an open source web conferencing system. Starting in version 2.2 and prior to versions 2.3.18 and 2.4-rc-6, an attacker who is able to obtain the meeting identifier for a meeting on a server can find information related to an external video being shared, like the current timestamp and play/pause. The problem has been patched in versions 2.3.18 and 2.4-rc-6 by modifying the stream to send the data only for users in the meeting. There are currently no known workarounds.