CVE-2021-42043 : Security Advisory and Response

A security issue was found in Special:MediaSearch in the MediaWiki through version 1.36.2, allowing for injection and execution of HTML and JavaScript.

Understanding CVE-2021-42043

This CVE involves a vulnerability in the MediaSearch extension of MediaWiki, potentially enabling the injection of malicious scripts.

What is CVE-2021-42043?

The issue exists in the suggestion text parameter of MediaSearch, enabling the execution of HTML and JavaScript through certain search operators.

The Impact of CVE-2021-42043

Malicious actors can exploit this vulnerability to execute arbitrary code, potentially leading to cross-site scripting (XSS) attacks and unauthorized data access.

Technical Details of CVE-2021-42043

This section provides detailed technical information about the CVE.

Vulnerability Description

The vulnerability arises from inadequate sanitization of suggestion text in Special:MediaSearch, facilitating the injection and execution of HTML and JavaScript code.

Affected Systems and Versions

MediaWiki versions up to 1.36.2 are impacted by this vulnerability.

Exploitation Mechanism

Attackers can leverage the 'intitle:' search operator within the query to inject and execute malicious HTML and JavaScript code.

Mitigation and Prevention

Protecting systems from CVE-2021-42043 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update MediaWiki to version 1.36.3 or later to mitigate this vulnerability.
Restrict access to the affected functionality to authorized users only.

Long-Term Security Practices

Regularly monitor and audit the application for any unauthorized changes or suspicious activities.
Educate users and administrators about secure coding practices and the risks associated with untrusted input.

Patching and Updates

Apply security patches provided by MediaWiki promptly to address known vulnerabilities and enhance system security.