BigBlueButton before 2.2.6 allows remote attackers to read arbitrary files because the presfilename (lowercase) value can be a .pdf filename while the presFilename (mixed case) value has a ../ sequence. This can be leveraged for privilege escalation via a directory traversal to bigbluebutton.properties. NOTE: this issue exists because of an ineffective mitigation to CVE-2020-12112 in which there was an attempted fix within an NGINX configuration file, without considering that the relevant part of NGINX is case-insensitive.

BigBlueButton through 2.2.28 uses Ghostscript for processing of uploaded EPS documents, and consequently may be subject to attacks related to a "schwache Sandbox."

BigBlueButton before 2.2.7 does not have a protection mechanism for separator injection in meetingId, userId, and authToken.

Greenlight is an end-user interface for BigBlueButton servers. Versions prior to 2.13.0 have an open redirect vulnerability in the Login page due to unchecked the value of the returnto cookie. Versions 2.13.0 contains a patch for the issue.

Greenlight is an end-user interface for BigBlueButton servers. Versions prior to 2.13.0 have an open redirect vulnerability in the Login page due to unchecked the value of the returnto cookie. Versions 2.13.0 contains a patch for the issue.

BigBlueButton Greenlight before 2.5.6 allows HTTP header (Host and Origin) attacks, which can result in Account Takeover if a victim follows a spoofed password-reset link.

BigBlueButton is an open-source virtual classroom. BigBlueButton prior to version 2.6.0-beta.2 is vulnerable to unrestricted file upload, where the insertDocument API call does not validate the given file extension before saving the file, and does not remove it in case of validation failures. BigBlueButton 2.6.0-beta.2 contains a patch. There are no known workarounds.

BigBlueButton is an open-source virtual classroom. Prior to 3.0.23, BigBlueButton allowed authenticated moderators to inject SQL through the meetingId and userId values used by refreshBreakoutRoomsVisibleForUsers in akka-bbb-apps/src/main/scala/org/bigbluebutton/core/db/BreakoutRoomUserDAO.scala. The method interpolated those values into breakout room visibility queries, allowing arbitrary SQL execution against the application database. This issue is fixed in version 3.0.23.

The installation procedure in BigBlueButton before 2.2.28 (or earlier) uses ClueCon as the FreeSWITCH password, which allows local users to achieve unintended FreeSWITCH access.

BigBlueButton is an open-source virtual classroom. In versions 3.0.21 and below, the official documentation for "Server Customization" on Support for ClamAV as presentation file scanner contains instructions that leave a BBB server vulnerable for Denial of Service. The flawed command exposes both ports (3310 and 7357) to the internet. A remote attacker can use this to send complex or large documents to clamd and waste server resources, or shutdown the clamd process. The clamd documentation explicitly warns about exposing this port. Enabling ufw (ubuntu firewall) during install does not help, because Docker routes container traffic through the nat table, which is not managed or restricted by ufw. Rules installed by ufw in the filter table have no effect on docker traffic. In addition, the provided example also mounts /var/bigbluebutton with write permissions into the container, which should not be required. Future vulnerabilities in clamd may allow attackers to manipulate files in that folder. Users are unaffected unless they have opted in to follow the extra instructions from BigBlueButton's documentation. This issue has been fixed in version 3.0.22.

BigBlueButton is an open-source virtual classroom. Prior to 3.0.21, bbb-web checksum validation could be bypassed when a presentationUploadExternalUrl parameter was supplied to API request handling in CreateMeeting.java and ValidationService.java, allowing a user to send valid requests to some endpoints without a checksum. This issue is fixed in version 3.0.21.

BigBlueButton is an open-source virtual classroom. Prior to 3.0.21, bbb-web generated conference sessionToken values with insufficiently secure randomness in bbb-common-web/src/main/java/org/bigbluebutton/api/Util.java and bigbluebutton-web/grails-app/controllers/org/bigbluebutton/web/controllers/ApiController.groovy, allowing a session user to predict other users' conference session tokens and impersonate them. This issue is fixed in version 3.0.21.

Cross-site Scripting (XSS) - Generic in GitHub repository bigbluebutton/bigbluebutton prior to 2.4.0.

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 feature's 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.

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 crash the chat functionality for all participants in a meeting by sending a malformed reactionEmojiId in the GraphQL mutation chatSendMessageReaction. Version 3.0.13 contains a patch. No known workarounds are available.

BigBlueButton through 2.2.28 uses STUN/TURN resources from a third party, which may represent an unintended endpoint.

An issue was discovered in BigBlueButton through 2.2.29. When at attacker is able to view an accountactivations/edit?token= URI, the attacker can create an approved user account associated with an email address that has an arbitrary domain name.

BigBlueButton before 2.2.27 has an unsafe JODConverter setting in which LibreOffice document conversions can access external files.

The installation procedure in BigBlueButton before 2.2.28 (or earlier) exposes certain network services to external interfaces, and does not automatically set up a firewall configuration to block external access.

BigBlueButton before 2.2.5 allows remote attackers to obtain sensitive files via Local File Inclusion.

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.

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 virtual classroom. In versions prior to 3.0.13, the "Shared Notes" feature contains a Stored Cross-Site Scripting (XSS) vulnerability with the input location being the "Username" field and the output location on the "Shared Notes" page, when a user with a malicious username is editing content. This vulnerability allows a low-privileged user to execute arbitrary JavaScript in the context of higher-privileged users (e.g., Admins) who open the Shared Notes page. Version 3.0.13 fixes the issue.

BigBlueButton is an open-source virtual classroom. Prior to 3.0.23, BigBlueButton exposed /bigbluebutton/api/handleJoinExistingUser through bigbluebutton-web/grails-app/controllers/org/bigbluebutton/web/controllers/ApiController.groovy. A requester able to supply an existingUserID for an active participant could reuse that participant's session and impersonate the participant in the same meeting because handleJoinExistingUser was a routable controller action rather than a private helper. This issue is fixed in version 3.0.23.

BigBlueButton is an open-source virtual classroom. Prior to 3.0.23, the presentation URL validation did not properly restrict access to site local and link local addresses. The redirect following logic now pins resolved IPs. This issue is fixed in version 3.0.23.

BigBlueButton is an open-source virtual classroom. Versions prior to 3.0.24 have a missing authorization that allows viewers to inject/overwrite captions Version 3.0.24 tightened the permissions on who is able to submit captions. No known workarounds are available.

BigBlueButton is an open-source virtual classroom. In versions prior to 3.0.19, the recording playback (presentation format) was not sanitizing user's input in public chat. This allowed for a malicious actor to craft and carry out a targeted XSS attack, activated on anyone replaying the recording. This issue has been fixed 3.0.19.

In BigBlueButton before 2.2.28 (or earlier), the client-side Mute button only signifies that the server should stop accepting audio data from the client. It does not directly configure the client to stop sending audio data to the server, and thus a modified server could store the audio data and/or transmit it to one or more meeting participants or other third parties.

BigBlueButton before 2.3 does not implement LibreOffice sandboxing. This might make it easier for remote authenticated users to read the API shared secret in the bigbluebutton.properties file. With the API shared secret, an attacker can (for example) use api/join to join an arbitrary meeting regardless of its guestPolicy setting.

BigBlueButton before 2.2.7 allows remote authenticated users to read local files and conduct SSRF attacks via an uploaded Office document that has a crafted URL in an ODF xlink field.