CVE-2019-18210 : What You Need to Know

Persistent Cross-Site Scripting (XSS) vulnerability in Moodle platform up to version 3.7.2 allows authenticated users to inject JavaScript code into other users' sessions.

Understanding CVE-2019-18210

An issue of Persistent Cross-Site Scripting (XSS) has been identified in the /course/modedit.php file of the Moodle platform up to version 3.7.2.

What is CVE-2019-18210?

Authenticated users with a role of Teacher or higher can inject JavaScript code into the session of another user by manipulating the introeditor[text] parameter.
There is a disagreement between the discoverer and the vendor regarding whether Teachers should have the ability to add arbitrary JavaScript.

The Impact of CVE-2019-18210

Allows attackers to execute malicious scripts in the context of other users, potentially leading to unauthorized actions.

Technical Details of CVE-2019-18210

Persistent XSS vulnerability in Moodle platform.

Vulnerability Description

Authenticated users (Teacher and above) can inject JavaScript into the session of another user via the introeditor[text] parameter.

Affected Systems and Versions

Moodle platform up to version 3.7.2.

Exploitation Mechanism

Manipulating the introeditor[text] parameter allows injecting malicious JavaScript code.

Mitigation and Prevention

Steps to address the CVE-2019-18210 vulnerability.

Immediate Steps to Take

Upgrade Moodle to a patched version.
Educate users about the risks of executing arbitrary scripts.

Long-Term Security Practices

Regularly update Moodle to the latest version.
Implement strict input validation to prevent XSS attacks.

Patching and Updates

Apply security patches provided by Moodle to fix the vulnerability.