CVE-2021-24871 Explained : Impact and Mitigation

The Get Custom Field Values WordPress plugin before version 4.0.1 is vulnerable to Cross-Site Scripting attacks due to improper handling of custom fields.

Understanding CVE-2021-24871

This CVE pertains to a security issue in the Get Custom Field Values WordPress plugin that allows users with the role of contributor or higher to execute Cross-Site Scripting attacks.

What is CVE-2021-24871?

The vulnerability in the Get Custom Field Values plugin, before version 4.0.1, arises from the lack of proper escaping of custom fields before displaying them on web pages. This flaw enables malicious contributors or higher-level users to inject and execute arbitrary JavaScript code, putting website visitors at risk of various attacks.

The Impact of CVE-2021-24871

As a result of this security issue, attackers with low-level access privileges can manipulate custom fields to launch Cross-Site Scripting attacks, potentially compromising the integrity of the affected WordPress websites and endangering user data.

Technical Details of CVE-2021-24871

This section delves into the specific technical aspects of the CVE-2021-24871 vulnerability.

Vulnerability Description

The vulnerability in the Get Custom Field Values plugin stems from the plugin's failure to properly sanitize and escape custom fields, opening the door for malicious actors to inject malicious scripts.

Affected Systems and Versions

The affected version of the Get Custom Field Values plugin is any version prior to 4.0.1. Websites using versions earlier than this are exposed to the Cross-Site Scripting risk.

Exploitation Mechanism

By exploiting this vulnerability, attackers with contributor or higher privileges can input malicious code into custom fields, leading to the execution of unauthorized scripts on website pages.

Mitigation and Prevention

Protect your WordPress websites from CVE-2021-24871 by following these essential security measures.

Immediate Steps to Take

Update the Get Custom Field Values plugin to version 4.0.1 or later to patch the vulnerability and prevent XSS attacks.
Regularly monitor and review user permissions to restrict untrusted users from exploiting this security flaw.

Long-Term Security Practices

Educate your team members on secure coding practices, emphasizing the importance of input validation and output escaping.
Implement a Web Application Firewall (WAF) to mitigate XSS vulnerabilities and other common web-based attack vectors.

Patching and Updates

Stay abreast of security updates for the Get Custom Field Values plugin and apply patches promptly to safeguard your WordPress site against known vulnerabilities.