CVE-2023-43797 : Vulnerability Insights and Analysis

BigBlueButton Stored Cross-site Scripting vulnerability at Guest Lobby

Understanding CVE-2023-43797

BigBlueButton, an open-source virtual classroom platform, was found to have a Stored Cross-site Scripting (XSS) vulnerability in the Guest Lobby feature.

What is CVE-2023-43797?

The CVE-2023-43797 vulnerability affected BigBlueButton versions prior to 2.6.11 and 2.7.0-beta.3, allowing attackers to execute malicious scripts by inserting unsanitized messages into the meeting lobby page using unsafe innerHTML. This vulnerability was addressed in later versions by implementing text sanitization for lobby messages.

The Impact of CVE-2023-43797

The impact of this vulnerability could lead to unauthorized execution of scripts in the context of a user's browser, potentially compromising the security and integrity of the platform. Attackers could exploit this to perform actions on behalf of users, steal sensitive information, or carry out other malicious activities.

Technical Details of CVE-2023-43797

Vulnerability Description

The vulnerability stemmed from the improper handling of user input, allowing malicious actors to inject and execute scripts within the Guest Lobby of BigBlueButton prior to the specified patched versions.

Affected Systems and Versions

BigBlueButton versions before 2.6.11 and 2.7.0-beta.3 were impacted by this vulnerability. Users of these versions were at risk of falling victim to cross-site scripting attacks through the Guest Lobby feature.

Exploitation Mechanism

Attackers could exploit this vulnerability by inserting specially crafted scripts into unsanitized messages displayed in the meeting lobby. This could result in the unauthorized execution of scripts in the context of the user's browser.

Mitigation and Prevention

Immediate Steps to Take

To mitigate the risk associated with CVE-2023-43797, users are strongly advised to update their BigBlueButton installations to versions 2.6.11 or 2.7.0-beta.3 and above. Additionally, users should exercise caution while interacting with messages displayed in the Guest Lobby to prevent script execution.

Long-Term Security Practices

In the long term, organizations should implement secure coding practices, including input validation and output sanitization, to prevent cross-site scripting vulnerabilities. Regular security audits and timely software updates are essential to maintain the integrity of virtual classroom platforms.

Patching and Updates

BigBlueButton addressed the CVE-2023-43797 vulnerability by implementing text sanitization for lobby messages in versions 2.6.11 and 2.7.0-beta.3. Users are encouraged to stay informed about security advisories and promptly apply patches and updates to protect their systems.