Bigbluebutton: >> Bigbluebutton >> 2.4.0 Security Vulnerabilities
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.
CVSS Score
4.8
EPSS Score
0.001
Published
2023-06-26
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
CVSS Score
2.7
EPSS Score
0.002
Published
2022-12-16
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.
CVSS Score
4.3
EPSS Score
0.002
Published
2022-12-16
BigBlueButton is an open source web conferencing system. Users in meetings with private chat enabled are vulnerable to a cross site scripting attack in affected versions. The attack occurs when the attacker (with xss in the name) starts a chat. in the victim's client the JavaScript will be executed. This issue has been addressed in version 2.4.8 and 2.5.0. There are no known workarounds for this issue.
CVSS Score
6.5
EPSS Score
0.008
Published
2022-06-27
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.
CVSS Score
6.5
EPSS Score
0.003
Published
2022-06-27
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.
CVSS Score
5.4
EPSS Score
0.002
Published
2022-06-24
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.
CVSS Score
4.3
EPSS Score
0.003
Published
2022-06-02
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.
CVSS Score
7.5
EPSS Score
0.007
Published
2022-06-01
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