CVE-2020-12443 : Security Advisory and Response

BigBlueButton before 2.2.6 has a vulnerability that allows remote attackers to read arbitrary files, potentially leading to privilege escalation through directory traversal.

Understanding CVE-2020-12443

BigBlueButton before version 2.2.6 is susceptible to a security issue that enables attackers to access unauthorized files on the system.

What is CVE-2020-12443?

This CVE describes a flaw in BigBlueButton versions prior to 2.2.6 that permits attackers to read arbitrary files due to a case-insensitive NGINX configuration, potentially leading to privilege escalation.

The Impact of CVE-2020-12443

The vulnerability allows remote attackers to exploit the system and gain unauthorized access to sensitive files, potentially escalating their privileges within the system.

Technical Details of CVE-2020-12443

BigBlueButton's security flaw is detailed below:

Vulnerability Description

Attackers can leverage the presfilename value to access .pdf files and presFilename to perform directory traversal, leading to unauthorized access.

Affected Systems and Versions

BigBlueButton versions before 2.2.6 are affected by this vulnerability.

Exploitation Mechanism

Attackers exploit the case-insensitive NGINX configuration to perform privilege escalation through directory traversal.

Mitigation and Prevention

Steps to address and prevent the CVE-2020-12443 vulnerability:

Immediate Steps to Take

Upgrade BigBlueButton to version 2.2.6 or higher to mitigate the vulnerability.
Monitor system logs for any suspicious activities indicating unauthorized access.

Long-Term Security Practices

Implement strict file access controls and regularly review and update system configurations.
Conduct security audits and penetration testing to identify and address any potential vulnerabilities.

Patching and Updates

Apply security patches promptly and keep all software and systems up to date to prevent exploitation of known vulnerabilities.