CVE-2019-3850 : What You Need to Know

A vulnerability was discovered in earlier versions of Moodle, specifically versions 3.6.3, 3.5.5, 3.4.8, and 3.1.17, where links within assignment submission comments could be exploited due to the absence of the no-referrer header policy.

Understanding CVE-2019-3850

This CVE pertains to a weakness found in Moodle versions 3.6.3, 3.5.5, 3.4.8, and 3.1.17, making them susceptible to potential exploits.

What is CVE-2019-3850?

The vulnerability in earlier versions of Moodle allowed links in assignment submission comments to open directly in the same window, increasing the risk of potential exploits despite the links being potentially legitimate.

The Impact of CVE-2019-3850

The vulnerability's base score is 4.3, with a medium severity rating. It has low attack complexity and vector, impacting integrity and requiring low privileges.

Technical Details of CVE-2019-3850

This section provides more in-depth technical insights into the CVE.

Vulnerability Description

The vulnerability in Moodle versions 3.6.3, 3.5.5, 3.4.8, and 3.1.17 allowed links in assignment submission comments to open in the same window, increasing the risk of potential exploits.

Affected Systems and Versions

Affected Product: Moodle
Affected Versions: 3.6.3, 3.5.5, 3.4.8, 3.1.17

Exploitation Mechanism

The vulnerability was exploited by opening links within assignment submission comments directly in the same window, combined with the absence of the no-referrer header policy.

Mitigation and Prevention

Protecting systems from CVE-2019-3850 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Moodle to the latest version to patch the vulnerability.
Implement a Content Security Policy (CSP) to control how resources are loaded on your site.
Educate users about the risks of clicking on unknown links.

Long-Term Security Practices

Regularly update and patch all software and plugins to prevent vulnerabilities.
Monitor and restrict external links within Moodle to minimize potential risks.

Patching and Updates

Ensure timely installation of security patches and updates to keep Moodle secure from known vulnerabilities.