CVE-2021-21318 : Security Advisory and Response

Opencast is a free, open-source platform used for managing educational audio and video content. A vulnerability in Opencast versions before 9.2 allows for an easy denial of access to series metadata and content, affecting user access to educational materials.

Understanding CVE-2021-21318

This vulnerability in Opencast < 9.2 impacts the availability of educational content and metadata, potentially leading to broader access rules than intended.

What is CVE-2021-21318?

Opencast versions prior to 9.2 have a flaw where strict access rules set for an episode can overwrite series access, hiding the series from users without superuser privileges. This can result in unauthorized access to series metadata and content.

The Impact of CVE-2021-21318

The vulnerability allows users with lower privileges to deny access to series metadata and content, impacting the accessibility and visibility of educational materials managed through Opencast.

Technical Details of CVE-2021-21318

Opencast versions below 9.2 are affected by an authorization issue that can lead to unauthorized access and denial of service.

Vulnerability Description

Publishing an episode with strict access rules can overwrite series access, potentially hiding the series from users without superuser privileges, affecting educational content visibility.

Affected Systems and Versions

Opencast versions earlier than 9.2 are vulnerable to this issue, impacting the management and accessibility of educational audio and video content.

Exploitation Mechanism

Unauthorized users can exploit this vulnerability by publishing episodes with specific access rules, leading to the denial of access to educational content and series metadata.

Mitigation and Prevention

Organizations using Opencast should take immediate steps to address this vulnerability and ensure the security of educational materials.

Immediate Steps to Take

Update Opencast to version 9.2 or newer to mitigate the vulnerability and prevent unauthorized access to series metadata and content.

Long-Term Security Practices

Implement strict access controls, regularly update software, and educate users on secure data management practices to enhance overall security.

Patching and Updates

Regularly monitor for security advisories and apply patches promptly to prevent unauthorized access and ensure the protection of educational content.