CVE-2021-46150 : What You Need to Know

MediaWiki before versions 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37.1 is affected by an XSS vulnerability in Special:CheckUserLog. This allows CheckUser XSS due to date mishandling.

Understanding CVE-2021-46150

This CVE identifies an XSS vulnerability in MediaWiki that can be exploited through Special:CheckUserLog due to improper date handling.

What is CVE-2021-46150?

CVE-2021-46150 is a security flaw in MediaWiki versions prior to 1.35.5, 1.36.3, and 1.37.1 that enables XSS attacks through the CheckUser feature when handling dates.

The Impact of CVE-2021-46150

The vulnerability allows malicious actors to execute XSS attacks by manipulating dates within the Special:CheckUserLog function in MediaWiki, potentially leading to unauthorized access or data theft.

Technical Details of CVE-2021-46150

MediaWiki's vulnerability can be better understood through its technical aspects.

Vulnerability Description

The issue arises from the mishandling of dates in MediaWiki's Special:CheckUserLog feature, leading to XSS execution by inserting malicious payloads.

Affected Systems and Versions

All MediaWiki versions before 1.35.5, 1.36.3, and 1.37.1 are susceptible to this XSS vulnerability through the Special:CheckUserLog.

Exploitation Mechanism

The XSS exploitation occurs when an attacker submits a crafted payload containing scripts via the date field in the Special:CheckUserLog page.

Mitigation and Prevention

Preventive measures and actions can help mitigate the risks associated with CVE-2021-46150.

Immediate Steps to Take

Update MediaWiki to the latest patched versions (1.35.5, 1.36.3, 1.37.1) to eliminate the XSS vulnerability.
Restrict access to the Special:CheckUserLog feature to authorized users only.
Regularly monitor logs and user activities for any unusual XSS attempts.

Long-Term Security Practices

Implement secure coding practices to sanitize and validate user inputs effectively.
Conduct regular security assessments and penetration testing to identify and address vulnerabilities proactively.

Patching and Updates

Apply official patches and updates released by MediaWiki promptly to ensure the system is protected against known vulnerabilities.