Reporting Security Vulnerabilities in the WP Opal Membership Plugin
The security of WordPress plugins is a critical aspect of maintaining the integrity and trustworthiness of any website. With over 50,000 plugins available, WordPress offers an extensive range of tools to extend a website’s functionality. However, not all plugins are created equal when it comes to security, and some may have vulnerabilities that, if exploited, could result in serious security breaches. One such plugin that has come under scrutiny recently is the WP Opal Membership plugin.
The WP Opal Membership plugin provides website owners with the ability to create and manage membership-based websites. It offers users features like membership subscriptions, payment options, and content restrictions.
However, our team has analysed the plugin codebase and found a security vulnerability within it. We reported the issue to the WordPress team, who subsequently closed the plugin after the developers failed to respond to our findings. Our reports were accepted by Wordfence, and Loop Digital has been assigned two CVE entries in recognition of this discovery.
In this article, we will explore two significant security vulnerabilities that we have found in the WP Opal Membership plugin:
Improper Data Access Control
Stored Cross-Site Scripting
We will explain what these vulnerabilities are, their potential impact, and how to address them with practical, actionable solutions. This guide is designed to assist both developers and website administrators in understanding and mitigating these risks to ensure the safety and privacy of user data.
What is the WP Opal Membership Plugin?
For those unfamiliar with the WP Opal Membership plugin, it is a WordPress plugin that enables website owners to create subscription-based membership systems. The plugin allows users to register, subscribe, and access exclusive content behind a paywall or restricted membership tier.
What is CVE Entry?
A Common Vulnerabilities and Exposures (CVE) entry is a public reference used to identify and describe security vulnerabilities. Each CVE is assigned a unique identifier (e.g., CVE-2023-12345), making it easier for developers and security experts to track and address specific vulnerabilities across software systems.
Understanding Security Vulnerabilities
Before diving into the specifics of the vulnerabilities in the WP Opal Membership plugin, it’s essential to understand what security vulnerabilities are and why they matter for any website, especially those using WordPress.
Security vulnerabilities are weaknesses or flaws in a system that can be exploited by hackers or malicious users to gain unauthorised access to data or systems. When these vulnerabilities are present in a WordPress plugin, they can expose sensitive data, cause site downtime, or even lead to a complete site takeover. In the case of the WP Opal Membership plugin, vulnerabilities have been identified that could compromise the privacy of user information, including payment notes.
Maintaining a secure website is not just a technical necessity but a critical part of building trust with your users. A single vulnerability can lead to:
Data Breaches: Sensitive user data like emails, addresses, and payment information could be exposed.
Reputation Damage: Users will lose trust in your site, which can harm your brand.
Loss of Revenue: Site downtime or loss of user trust can lead to a decrease in conversions and subscriptions.
With this in mind, let’s explore the two major vulnerabilities identified in the WP Opal Membership plugin.
1. Improper Data Access Control
Vulnerability Overview
Authentication Level Required: Subscriber
Vulnerability Description: The WP Opal Membership plugin allows logged-in subscribers to view payment notes intended for administrative access only. These payment notes often contain private and sensitive information, such as transaction details or customer data. They are stored as comments in the WordPress wp_comments table. However, despite being tagged with a custom comment type, these payment notes appear in the ‘recent comments’ widget within the WordPress dashboard, making them visible to users who should not have access to them.
Understanding Data Access Control
Data Access Control is the method of regulating who can access certain types of information based on their roles or permissions. For instance, only administrators should have access to sensitive payment information, while regular users (such as subscribers) should not be able to view this data.
Why Is This Important?
Improper data access control can lead to data breaches where sensitive information is exposed to individuals who should not have access to it. In the case of the WP Opal Membership plugin, this vulnerability means that private payment notes, which should only be seen by the website administrator, can be viewed by regular users (subscribers). This flaw compromises the privacy of both administrators and customers.
Uncontrolled access to sensitive data can result in:
Privacy Violations: Personal or payment details of customers can be viewed by unauthorised users.
Data Breaches: Sensitive company data, such as financial transactions, could be exposed.
Loss of Trust: Users are less likely to trust a website if they know that their private information is not secure.
Cause of the Vulnerability
The root cause of this vulnerability lies in how the WP Opal Membership plugin handles the saving of payment notes. These notes are stored as comments in the wp_comments table, and while they use a custom comment type (payment_notes), they are still accessible through standard WordPress comment functionalities, such as the ‘recent comments’ widget in the dashboard. This means subscribers can inadvertently view private notes meant only for administrators.
Recommended Action
Given the severity of this vulnerability, we strongly advise uninstalling the WP Opal Membership plugin immediately and seeking an alternative solution. The issue cannot be fully resolved through code revisions alone, and continued use of the plugin poses a security risk.
2. Unauthenticated Stored Cross-Site Scripting
Vulnerability Overview
Authentication Level Required: Subscriber
Vulnerability Description: The WP Opal Membership plugin does not properly sanitise input fields in the checkout form. As a result, users can inject JavaScript code into fields such as ‘First Name’, ‘Last Name’, ‘Company Name’, ‘Address’, ‘Address 2’, and ‘Town’. Once the checkout process is complete, the injected scripts are executed on the ‘Payment History’ page in the front end.
Understanding Cross-Site Scripting
Cross-Site Scripting (XSS) is a type of security vulnerability that allows attackers to inject malicious code (usually JavaScript) into web pages viewed by other users. There are different types of XSS vulnerabilities:
Stored XSS: The malicious code is permanently stored on the target server (e.g., in a database) and is executed every time the page is viewed.
Self-XSS: A variant where the user unintentionally injects code into a form or field that gets executed when they later view the content.
Cause of the Vulnerability
The vulnerability is caused by the plugin’s failure to sanitise user input on the checkout form. This allows malicious scripts to be injected into fields like ‘First Name’ or ‘Address’. These scripts are stored and later executed when the user views their payment history, creating a potential attack vector.
Recommended Action
We strongly recommend uninstalling the WP Opal Membership plugin as soon as possible. Alternatively, you may wish to hire a developer to assist in creating a custom patch to mitigate the issue.
How Do These Vulnerabilities Affect You?
For website administrators and business owners, not addressing these vulnerabilities could have severe real-world consequences. Here’s how these security issues can affect you:
Improper Data Access Control: Private payment information, such as transaction notes, could be exposed to subscribers or other unauthorised users. This not only compromises customer data but also violates privacy regulations.
Stored XSS: Malicious scripts injected into forms by users could be executed, leading to the potential theft of data or unauthorised actions taken on the website. Although this seems like a self-inflicted vulnerability, it can still cause significant damage.
Failure to address these vulnerabilities could result in data breaches, loss of customer trust, and possible legal repercussions if sensitive user data is exposed.
Our team’s research into these vulnerabilities has been recognised by Wordfence, resulting in the assignment of two CVE entries:
Our recognition of the vulnerabilities indicated the importance of promptly addressing these security issues to safeguard your website and users’ information.
Tips for Business Owners to Secure Their Sites
Even if you are not a developer, there are several steps you can take to protect your WordPress website from vulnerabilities like the ones described above:
Update Regularly: Always keep WordPress, themes, and plugins up to date. Security patches are often included in updates to address known vulnerabilities.
Install a Security Plugin: Use tools like Wordfence or Sucuri to scan your site for vulnerabilities and receive alerts if any are found.
Limit Plugin Use: Only install plugins from trusted sources, and remove any plugins that are not actively used. The more plugins you have, the higher the risk of vulnerabilities.
Backup Frequently: Ensure that you regularly back up your website so that you can restore it in case of a security breach or error.
Consult a Developer: If you are not sure how to address a vulnerability, consult a professional developer or a security expert to help secure your website.
Safeguard Your Website with Loop Digital
The identified vulnerabilities in the WP Opal Membership plugin—Improper Data Access Control and Stored XSS—pose significant risks to the security and privacy of users’ information. By implementing the revised code snippets provided above and following best practices, you can protect your site from these vulnerabilities and ensure that your users’ data remains safe.
Whether you’re a developer or a website owner, regular security audits and proactive maintenance are essential in today’s digital landscape. If you encounter any challenges in implementing these fixes or require further assistance, don’t hesitate to reach out to a security expert.
By staying vigilant and proactive, you can safeguard your website against vulnerabilities and provide a secure environment for all users.
While the WP Opal Membership plugin offers a range of features for membership websites, its security flaws cannot be overlooked. It’s essential to stay proactive and vigilant about potential vulnerabilities that could compromise your website.
By identifying and addressing issues such as improper data access control and Stored XSS, you can ensure that your site remains safe for both you and your users. Regular updates, security audits, and best practices will help mitigate these risks.
At Loop Digital, we understand the importance of keeping your website secure. In addition to providing hosting and maintenance services, we offer expert web design and website improvement solutions tailored to your business needs. Our team is ready to help protect your site from vulnerabilities like these and ensure it continues to function optimally.
If you’d like to learn more about how we can help safeguard your website, book a free consultation with us today. Together, we can create a secure, high-performing digital environment for your business.
Karolina’s speciality and also her biggest passion is web development. She has a BSc in Economics with Management (Aberystwyth University). She also has a Master degree in Computing (Web Technologies and Internet Security) and Karolina passed this one with distinction (it was at University of Northampton). Her business background consists of working as a web dev firstly as a freelancer, then she joined Loop in 2019. Karolina can help with building sites from scratch, adding new functionality to the existing sites, and she love investigating and fixing errors.
Fun facts: secretly she enjoys watching Paw Patrol, family says she often asks obvious questions!
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