CVE-2021-46146 Explained : Impact and Mitigation

An issue was discovered in MediaWiki before 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37.1. The WikibaseMediaInfo component is vulnerable to XSS via the caption fields for a given media file.

Understanding CVE-2021-46146

This CVE relates to a cross-site scripting vulnerability in MediaWiki's WikibaseMediaInfo component.

What is CVE-2021-46146?

CVE-2021-46146 is a security flaw in MediaWiki versions that allows attackers to execute malicious scripts via the caption fields of media files.

The Impact of CVE-2021-46146

This vulnerability could lead to unauthorized script execution, potentially compromising user data and system integrity.

Technical Details of CVE-2021-46146

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

Vulnerability Description

The issue lies in the inability of MediaWiki to properly validate caption fields in media files, enabling attackers to inject malicious scripts.

Affected Systems and Versions

MediaWiki versions before 1.35.5
MediaWiki 1.36.x before 1.36.3
MediaWiki 1.37.x before 1.37.1

Exploitation Mechanism

Attackers can exploit this vulnerability by inserting malicious scripts into the caption fields of media files, leading to XSS attacks.

Mitigation and Prevention

Protect your systems from CVE-2021-46146 with these mitigation strategies.

Immediate Steps to Take

Update MediaWiki to version 1.35.5, 1.36.3, or 1.37.1, which patch the vulnerability.
Sanitize user input to prevent script injection in caption fields.

Long-Term Security Practices

Regularly monitor and audit your web applications for vulnerabilities.
Educate users on safe practices to prevent XSS attacks.
Implement a web application firewall to filter and block malicious traffic.

Patching and Updates

Apply software patches promptly to ensure your system is protected from known vulnerabilities.