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.

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 can circumvent access restrictions for drawing on the whiteboard. The permission check is inadvertently skipped on the server, due to a previously introduced grace period. The attacker must be a meeting participant. The problem has been patched in versions 2.3.18 and 2.4-rc-6. There are currently no known workarounds.

BigBlueButton is an open source web conferencing system. Starting in version 2.2 and prior to versions 2.3.18 and 2.4.1, an attacker could send messages to a locked chat within a grace period of 5s any lock setting in the meeting was changed. The attacker needs to be a participant in the meeting. Versions 2.3.18 and 2.4.1 contain a patch for this issue. There are currently no known workarounds.

BigBlueButton is an open source web conferencing system. In BigBlueButton starting with 2.2 but before 2.3.18 and 2.4-rc-1, an attacker can circumvent access controls to gain access to all breakout rooms of the meeting they are in. The permission checks rely on knowledge of internal ids rather than on verification of the role of the user. Versions 2.3.18 and 2.4-rc-1 contain a patch for this issue. There are currently no known workarounds.

BigBlueButton is an open source web conferencing system. Starting with version 2.2 and prior to versions 2.3.9 and 2.4-beta-1, an attacker can circumvent access controls to obtain the content of public chat messages from different meetings on the server. The attacker must be a participant in a meeting on the server. BigBlueButton versions 2.3.9 and 2.4-beta-1 contain a patch for this issue. There are currently no known workarounds.

BigBlueButton is an open source web conferencing system. Versions starting with 2.2 and prior to 2.3.19, 2.4.7, and 2.5.0-beta.2 are vulnerable to regular expression denial of service (ReDoS) attacks. By using specific a RegularExpression, an attacker can cause denial of service for the bbb-html5 service. The useragent library performs checking of device by parsing the input of User-Agent header and lets it go through lookupUserAgent() (alias of useragent.lookup() ). This function handles input by regexing and attackers can abuse that by providing some ReDos payload using SmartWatch. The maintainers removed htmlclient/useragent from versions 2.3.19, 2.4.7, and 2.5.0-beta.2. As a workaround, disable NginX forwarding the requests to the handler according to the directions in the GitHub Security Advisory.