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.
An issue was discovered in BigBlueButton through 2.2.29. A brute-force attack may occur because an unlimited number of codes can be entered for a meeting that is protected by an access code.
An issue was discovered in BigBlueButton through 2.2.29. When at attacker is able to view an account_activations/edit?token= URI, the attacker can create an approved user account associated with an email address that has an arbitrary domain name.
web/controllers/ApiController.groovy in BigBlueButton before 2.2.29 lacks certain parameter sanitization, as demonstrated by accepting control characters in a user name.
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 2.2.28 (or earlier) does not set the secure flag for the session cookie in an https session, which makes it easier for remote attackers to capture this cookie by intercepting its transmission within an http session.
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.
In BigBlueButton before 2.2.28 (or earlier), uploaded presentations are sent to clients without a Content-Type header, which allows XSS, as demonstrated by a .png file extension for an HTML document.