CVE-2021-45473 : Security Advisory and Response

In MediaWiki through 1.37, Wikibase item descriptions allow XSS, triggered by visiting an action=info URL.

Understanding CVE-2021-45473

What is CVE-2021-45473?

MediaWiki through version 1.37 is vulnerable to a cross-site scripting (XSS) attack in Wikibase item descriptions when accessing an action=info URL.

The Impact of CVE-2021-45473

This vulnerability can be exploited by malicious actors to execute arbitrary script code in a victim's web browser, potentially leading to unauthorized actions or data theft.

Technical Details of CVE-2021-45473

Vulnerability Description

The XSS vulnerability arises from inadequate input validation of Wikibase item descriptions, allowing malicious scripts to be injected and executed.

Affected Systems and Versions

Systems running MediaWiki versions up to 1.37

Exploitation Mechanism

Malicious actors can craft a specially designed Wikibase item description to contain executable scripts, which are then executed when a user visits a specific URL.

Mitigation and Prevention

Immediate Steps to Take

Update MediaWiki to version 1.37 or apply the necessary security patches provided by the vendor.
Avoid visiting unknown or suspicious URLs.

Long-Term Security Practices

Regularly monitor and apply security updates for all software components.
Conduct security assessments to identify and address potential vulnerabilities in web applications.
Implement content security policies (CSP) to mitigate XSS risks.

Patching and Updates

MediaWiki users should promptly install security updates released by the vendor to address the XSS vulnerability.