CVE-2021-24381 Explained : Impact and Mitigation

A detailed analysis of the NinjaForms < 3.5.8.2 vulnerability that allows for Admin+ Stored Cross-Site Scripting.

Understanding CVE-2021-24381

This CVE relates to a security flaw in the Ninja Forms Contact Form WordPress plugin before version 3.5.8.2, enabling Cross-Site Scripting attacks.

What is CVE-2021-24381?

The Ninja Forms Contact Form plugin version < 3.5.8.2 fails to sanitize and escape the custom class name of form fields, enabling high privilege users to execute XSS attacks.

The Impact of CVE-2021-24381

The vulnerability allows attackers to inject malicious scripts through form fields, compromising the security of the WordPress site and potentially impacting user data.

Technical Details of CVE-2021-24381

An overview of the specifics of the vulnerability in NinjaForms.

Vulnerability Description

The issue stems from inadequate input validation on custom class names in form fields, permitting attackers to inject harmful code.

Affected Systems and Versions

Ninja Forms Contact Form plugin versions prior to 3.5.8.2 are susceptible to this security flaw.

Exploitation Mechanism

By crafting a specially designed form field with a malicious class name, threat actors can trigger XSS attacks even with restricted capabilities.

Mitigation and Prevention

Best practices to mitigate the risks associated with CVE-2021-24381.

Immediate Steps to Take

Users should update the Ninja Forms plugin to version 3.5.8.2 or above to patch the vulnerability and prevent exploitation.

Long-Term Security Practices

Implement strict input validation and security controls on web forms to prevent XSS vulnerabilities in the future.

Patching and Updates

Regularly check for plugin updates and apply patches promptly to ensure the security of WordPress websites.