XSS Vulnerability Discovered in Complianz WordPress GDPR/CCPA Cookie Consent Plugin
A recent discovery of a stored XSS vulnerability in the popular Complianz WordPress plugin has raised concerns for over 800,000 website installations. The vulnerability, which requires admin permission levels to execute, poses a potential risk to website visitors and site integrity. This article delves into the details of the vulnerability, its implications, and the recommended update to mitigate the risk.
Introduction
A stored XSS vulnerability has been uncovered in the Complianz WordPress GDPR/CCPA Cookie Consent plugin, a widely-used tool for privacy compliance with over 800,000 installations. This vulnerability has the potential to allow an attacker to upload and execute malicious scripts, posing a significant threat to website visitors and site security.
The Complianz plugin is designed to assist website owners in adhering to privacy regulations such as the General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA). It offers various privacy management features, including the blocking of third-party cookies, subregion-specific cookie consent, and comprehensive cookie banner management.
The widespread use of the Complianz plugin underscores its versatility and usefulness in addressing privacy compliance requirements, making the discovery of this vulnerability particularly concerning.
Understanding the Vulnerability
The stored XSS vulnerability in the Complianz WordPress plugin allows a user to upload a malicious script directly to the website server, presenting a significant security risk. Unlike reflected XSS vulnerabilities that require user interaction, stored XSS vulnerabilities involve the direct storage and serving of malicious scripts from the target website's server.
The vulnerability in the Complianz admin settings is attributed to a lack of two essential security functions: input sanitization and output escaping. Input sanitization, as defined by the official WordPress developer guide, involves the process of securing and filtering input data to ensure it meets expected criteria. Additionally, output escaping is a crucial security process that removes unwanted data before rendering it for the user.
The absence of these security measures in the plugin's code has exposed websites to potential exploitation, highlighting the critical importance of robust security practices in plugin development and maintenance.
Mitigating the Risk and Update Recommendation
The severity of the vulnerability is underscored by the requirement for attacker access at admin permission levels or higher. With a score of 4.4 out of 10, the vulnerability is deemed moderately serious, but its impact is limited to specific types of installations.
According to Wordfence, the vulnerability affects multi-site installations and instances where unfiltered_html has been disabled, further narrowing the scope of its impact. However, the potential for injected web scripts to execute on user-accessed pages warrants immediate attention and action.
To address the vulnerability, users are strongly advised to update their Complianz plugin to version 6.5.6 or higher. This update contains the necessary patches to mitigate the risk and secure affected installations against potential exploitation. By staying informed and promptly implementing the recommended update, website owners can safeguard their sites and protect their visitors from potential security threats.
