CVE-2021-43842 : Vulnerability Insights and Analysis

Wiki.js versions 2.5.257 and earlier are vulnerable to stored cross-site scripting through an SVG file upload. This allows malicious users to execute JavaScript on the site.

Understanding CVE-2021-43842

What is CVE-2021-43842?

Wiki.js, a Node.js-based wiki app, is prone to stored cross-site scripting through SVG file uploads. This vulnerability enables attackers to execute malicious scripts on the platform.

The Impact of CVE-2021-43842

The vulnerability can lead to unauthorized execution of JavaScript by malicious users, potentially compromising the security and integrity of the Wiki.js platform.

Technical Details of CVE-2021-43842

Vulnerability Description

The issue stems from improper handling of SVG file uploads, allowing attackers to embed malicious scripts for execution.

Affected Systems and Versions

Versions before 2.5.257 are vulnerable.
Versions < 2.5.258 (development) and < 2.5.260 (production) are affected.

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Network
Privileges Required: Low
User Interaction: Required

Mitigation and Prevention

Immediate Steps to Take

Update to Wiki.js version 2.5.260 or later that contains the patch.
Disable file uploads for non-trusted users as a temporary workaround.

Long-Term Security Practices

Regularly update Wiki.js to the latest versions.
Implement SVG sanitization measures.

Patching and Updates

Ensure all Wiki.js instances are updated to version 2.5.260 or above to mitigate the vulnerability.