CVE-2020-27608 : Security Advisory and Response

BigBlueButton before version 2.2.28 (or earlier) is vulnerable to XSS due to uploaded presentations being sent without a Content-Type header.

Understanding CVE-2020-27608

In this section, we will delve into the details of CVE-2020-27608.

What is CVE-2020-27608?

CVE-2020-27608 is a vulnerability in BigBlueButton that allows for XSS attacks by sending uploaded presentations without a Content-Type header, enabling malicious actors to execute scripts.

The Impact of CVE-2020-27608

The vulnerability in BigBlueButton could lead to cross-site scripting attacks, potentially compromising the confidentiality and integrity of user data.

Technical Details of CVE-2020-27608

Let's explore the technical aspects of CVE-2020-27608.

Vulnerability Description

Uploaded presentations in BigBlueButton lack a Content-Type header, enabling XSS attacks. For instance, a .png file extension can be used for an HTML document, leading to script execution.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Versions: All versions before 2.2.28

Exploitation Mechanism

The vulnerability arises from the lack of a Content-Type header in uploaded presentations, allowing attackers to disguise malicious scripts within different file types.

Mitigation and Prevention

Protecting systems from CVE-2020-27608 is crucial. Here are some steps to mitigate the risk.

Immediate Steps to Take

Update BigBlueButton to version 2.2.28 or later to patch the vulnerability.
Educate users about the risks of opening files from untrusted sources.

Long-Term Security Practices

Implement content security policies to prevent XSS attacks.
Regularly monitor and audit uploaded content for malicious scripts.

Patching and Updates

Stay informed about security updates for BigBlueButton and promptly apply patches to address known vulnerabilities.