BigBlueButton is an open source virtual classroom designed to help teachers teach and learners learn. In affected versions are affected by a Server-Side Request Forgery (SSRF) vulnerability. In an `insertDocument` API request the user is able to supply a URL from which the presentation should be downloaded. This URL was being used without having been successfully validated first. An update to the `followRedirect` method in the `PresentationUrlDownloadService` has been made to validate all URLs to be used for presentation download. Two new properties `presentationDownloadSupportedProtocols` and `presentationDownloadBlockedHosts` have also been added to `bigbluebutton.properties` to allow administrators to define what protocols a URL must use and to explicitly define hosts that a presentation cannot be downloaded from. All URLs passed to `insertDocument` must conform to the requirements of the two previously mentioned properties. Additionally, these URLs must resolve to valid addresses, and these addresses must not be local or loopback addresses. There are no workarounds. Users are advised to upgrade to a patched version of BigBlueButton.
BigBlueButton is an open source web conferencing system. Versions prior to 2.4-rc-6 are vulnerable to Insertion of Sensitive Information Into Sent Data. The moderators-only webcams lock setting is not enforced on the backend, which allows an attacker to subscribe to viewers' webcams, even when the lock setting is applied. (The required streamId was being sent to all users even with lock setting applied). This issue is fixed in version 2.4-rc-6. There are no workarounds.
BigBlueButton is an open source web conferencing system. Versions prior to 2.4.0 expose sensitive information to Unauthorized Actors. This issue affects meetings with polls, where the attacker is a meeting participant. Subscribing to the current-poll collection does not update the client UI, but does give the attacker access to the contents of the collection, which include the individual poll responses. This issue is patched in version 2.4.0. There are no workarounds.
BigBlueButton is an open source web conferencing system. Versions prior to 2.4.3 contain a whiteboard grace period that exists to handle delayed messages, but this grace period could be used by attackers to take actions in the few seconds after their access is revoked. The attacker must be a meeting participant. This issue is patched in version 2.4.3 an version 2.5-alpha-1
BigBlueButton is an open source web conferencing system. Versions prior to 2.4-rc-6, and 2.5-alpha-1 contain Incorrect Authorization for setting emoji status. A user with moderator rights can use the clear status feature to set any emoji status for other users. Moderators should only be able to set none as the status of other users. This issue is patched in 2.4-rc-6 and 2.5-alpha-1There are no workarounds.
BigBlueButton is an open source web conferencing system. Versions prior to 2.4-rc-6 are subject to Ineffective user bans. The attacker could register multiple users, and join the meeting with one of them. When that user is banned, they could still join the meeting with the remaining registered users from the same extId. This issue has been fixed by improving permissions such that banning a user removes all users related to their extId, including registered users that have not joined the meeting. This issue is patched in versions 2.4-rc-6 and 2.5-alpha-1. There are no workarounds.
BigBlueButton is an open source web conferencing system. Versions prior to 2.4.3, are subject to Insufficient Verification of Data Authenticity, resulting in Denial of Service. An attacker can make a Meteor call to `validateAuthToken` using a victim's userId, meetingId, and an invalid authToken. This forces the victim to leave the conference, because the resulting verification failure is also observed and handled by the victim's client. The attacker must be a participant in any meeting on the server. This issue is patched in version 2.4.3. There are no workarounds.
In BigBlueButton before 2.2.7, lockSettingsProps.disablePrivateChat does not apply to already opened chats. This occurs in bigbluebutton-html5/imports/ui/components/chat/service.js.
BigBlueButton version 2.4.7 (or earlier) is vulnerable to stored Cross-Site Scripting (XSS) in the private chat functionality. A threat actor could inject JavaScript payload in his/her username. The payload gets executed in the browser of the victim each time the attacker sends a private message to the victim or when notification about the attacker leaving room is displayed.