CVE-2022-31064 is a cross-site scripting (XSS) vulnerability identified in BigBlueButton, an open-source web conferencing system widely used for online meetings and virtual classrooms. The vulnerability specifically affects versions prior to 2.4.8. It arises from improper neutralization of user input during web page generation (CWE-79), allowing an attacker to inject malicious JavaScript code into the private chat feature of a meeting. When an attacker with the substring 'xss' in their username initiates a chat message, the malicious script executes in the victim's client browser. This can lead to unauthorized actions such as session hijacking, credential theft, or manipulation of the user interface. The vulnerability does not require prior authentication beyond joining a meeting with private chat enabled, and no user interaction beyond viewing the chat message is necessary for exploitation. The issue was addressed in BigBlueButton versions 2.4.8 and 2.5.0, with no known workarounds available for earlier versions. There are no known exploits in the wild at the time of reporting, but the vulnerability's nature makes it a significant risk in environments where BigBlueButton is used for sensitive communications.

For European organizations, the impact of this vulnerability can be substantial, especially for educational institutions, government bodies, and enterprises relying on BigBlueButton for secure communications. Exploitation could lead to unauthorized access to sensitive meeting content, leakage of confidential information, and potential compromise of user credentials. This could undermine trust in virtual collaboration platforms and disrupt critical operations. The vulnerability's exploitation could also facilitate further attacks within the network by enabling attackers to execute scripts that perform actions on behalf of the victim. Given the widespread adoption of BigBlueButton in European universities and public sector organizations, the risk of data breaches and privacy violations is heightened. Additionally, regulatory frameworks like GDPR impose strict requirements on data protection, and exploitation of this vulnerability could lead to compliance violations and associated penalties.

Organizations should prioritize upgrading BigBlueButton installations to version 2.4.8 or later immediately to remediate the vulnerability. Since no workarounds exist, patching is the primary defense. Additionally, administrators should audit user access controls to restrict meeting participation to trusted users and consider disabling private chat if feasible until the patch is applied. Implementing Content Security Policy (CSP) headers can help mitigate the impact of XSS by restricting the execution of unauthorized scripts. Monitoring network traffic and logs for unusual activity related to chat messages may help detect attempted exploitation. Training users to recognize suspicious behavior during meetings can also reduce risk. For organizations deploying BigBlueButton behind reverse proxies or web application firewalls (WAFs), configuring rules to detect and block suspicious script injections in chat messages can provide an additional layer of defense.