Medium · published June 27, 2022
BigBlueButton is an open source web conferencing system. In affected versions an attacker can embed malicious JS in their username and have it executed on the victim's client. When a user receives a private chat from the attacker (whose username contains malicious JavaScript), the script gets executed. Additionally when the victim receives a notification that the attacker has left the session. This issue has been patched in version 2.4.8 and 2.5.0. There are no known workarounds for this issue.