CVE-2021-36401 Explained : Impact and Mitigation

A local stored XSS risk was identified in Moodle due to inadequate sanitization of ID numbers exported in HTML data formats.

Understanding CVE-2021-36401

This section provides insights into the vulnerability impact, technical details, and mitigation strategies.

What is CVE-2021-36401?

CVE-2021-36401 refers to a vulnerability in Moodle that could lead to a local stored XSS risk when exporting ID numbers in HTML data formats without sufficient sanitization.

The Impact of CVE-2021-36401

The vulnerability allows malicious actors to execute arbitrary JavaScript code in the context of a user's session, potentially leading to data theft or unauthorized actions.

Technical Details of CVE-2021-36401

Explore the specifics of the vulnerability, including affected systems, exploitation mechanisms, and preventive measures.

Vulnerability Description

The issue arises from ID numbers exported in HTML data formats within Moodle, which lack proper sanitization procedures, enabling an attacker to inject malicious scripts.

Affected Systems and Versions

Moodle versions 3.11, 3.10 to 3.10.4, 3.9 to 3.9.7, and earlier unsupported versions are susceptible to this XSS risk.

Exploitation Mechanism

Attackers can exploit this vulnerability by manipulating ID numbers during HTML data export, inserting malicious scripts that execute upon interaction.

Mitigation and Prevention

Learn how to address the CVE-2021-36401 vulnerability and safeguard your Moodle instance.

Immediate Steps to Take

Users are advised to update their Moodle installations to the latest supported versions, ensuring all security patches are applied promptly.

Long-Term Security Practices

Maintain a proactive security posture by regularly monitoring for updates, conducting security audits, and educating users on best practices to prevent XSS attacks.

Patching and Updates

Stay informed about security advisories from Moodle and promptly apply patches to address known vulnerabilities.