CVE-2022-29233 is a medium-severity vulnerability affecting BigBlueButton, an open-source web conferencing system widely used for online meetings and virtual classrooms. The vulnerability exists in versions starting from 2.2 up to but not including 2.3.18, and from 2.4-alpha-1 up to but not including 2.4-rc-1. The root cause is improper authorization (CWE-285) due to the system relying on knowledge of internal identifiers (IDs) rather than robust role-based access control to enforce permissions. Specifically, an attacker who is a participant in a meeting can bypass access controls and gain unauthorized access to all breakout rooms within that meeting. Breakout rooms are typically isolated sub-sessions intended only for specific participants or groups. This flaw allows an attacker to view or potentially interact with breakout rooms they should not have access to, violating confidentiality and potentially integrity of the meeting content. The vulnerability does not require elevated privileges beyond being a meeting participant, nor does it require user interaction beyond joining the meeting. There are no known workarounds, but patched versions 2.3.18 and 2.4-rc-1 address this issue by implementing proper authorization checks based on user roles rather than internal IDs. No known exploits have been observed in the wild to date. The vulnerability was publicly disclosed on June 1, 2022, and has been enriched by CISA for awareness. Given the nature of BigBlueButton as a tool for education, corporate meetings, and government use, unauthorized access to breakout rooms could lead to leakage of sensitive discussions, confidential data, or intellectual property.

For European organizations, the impact of this vulnerability can be significant, especially for educational institutions, government agencies, and enterprises that rely on BigBlueButton for confidential communications. Unauthorized access to breakout rooms undermines the confidentiality of sensitive discussions, potentially exposing personal data, strategic plans, or proprietary information. This could lead to reputational damage, regulatory non-compliance (e.g., GDPR violations if personal data is exposed), and operational disruption if trust in the conferencing platform is eroded. The integrity of meeting content could also be compromised if unauthorized participants interfere or inject misleading information. Although availability is less directly impacted, the breach of access controls could prompt organizations to suspend or restrict use of BigBlueButton, affecting business continuity. The ease of exploitation—requiring only participation in a meeting—makes this vulnerability particularly concerning in open or large meetings where participant vetting is limited. The lack of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits over time.

European organizations should prioritize upgrading BigBlueButton installations to version 2.3.18 or later, or 2.4-rc-1 or later, where the authorization flaw has been patched. Since no workarounds exist, patching is the primary mitigation. Additionally, organizations should enforce strict meeting access controls, such as requiring authenticated users with verified identities and limiting meeting participation to trusted individuals. Implementing network segmentation and monitoring for unusual access patterns within meetings can help detect potential exploitation attempts. Administrators should review meeting configurations to minimize the use of breakout rooms or restrict their creation to trusted hosts until patches are applied. Logging and auditing of meeting activities should be enabled to facilitate incident response. For organizations unable to immediately patch, consider temporarily disabling breakout rooms or restricting their use to reduce exposure. Finally, raising user awareness about the risks of unauthorized access and encouraging reporting of suspicious meeting behavior can enhance detection and response capabilities.