APIs are the lifeline of modern applications, enabling seamless communication and integration across systems. However, their increasing adoption presents a range of security challenges that can have severe consequences for businesses. This article explores a real-life case study of a logistics company’s API breach, driven by GraphQL introspection, and offers valuable lessons for organizations to enhance their security posture. All information is shared with permission from the company and for educational purposes only.
The Double-Edged Sword of GraphQL Introspection
In most modern enterprise environments, two API architectures are predominantly used: RESTful APIs and GraphQL APIs. GraphQL APIs, with their flexible querying capabilities, have become a favorite among developers for their efficiency and ease of use. However, the introspection feature of GraphQL, while helpful for development, can unintentionally expose an API’s entire schema if not handled correctly in production environments. Introspection provides detailed metadata, including available queries, data types, and structures, which can reveal significant internal details to an attacker.
How MerkleFence Compromised the Logistics Company Without Login Access
The breach at a logistics company unfolded during what was initially a security assessment by MerkleFence. We found a vulnerable customer-facing GraphQL API while testing their iOS mobile app which was already live and available to the public! This company’s iOS app, designed to manage a complex network of operations, relied heavily on this GraphQL API. However, a single oversight—leaving introspection enabled in production—opened the door for us to discover a series of API security failures.
Step-by-Step Exploitation
- Discovery of Introspection:
The API’s introspection feature was left enabled in production, allowing us to query and uncover the full schema. The response from the GraphQL API endpoint revealed the structure of the API, detailing sensitive endpoint details such as available queries, mutations, subscriptions, types, and their relationships. Discovering the entire schema made it easier for us to identify potential vulnerabilities. This oversight was the first of many. We exported the schema to Postman, a tool commonly used for API testing and development, allowing us to craft and send requests, explore the API’s functionality in detail, and test for every vulnerability on the OWASP API Top 10 list.
- Exploitation of Authentication Flaws:
With schema details in hand, we identified endpoints lacking proper authentication checks. For instance, the ‘getOrders’ endpoint could be accessed using just a UserID, bypassing authentication altogether—a direct violation of best practices outlined in the OWASP API Security Top 10. This demonstrated the presence of the following vulnerabilities in this GraphQL API:
- Manipulation via Unauthenticated Endpoints:
In our assessment, we exploited endpoints like ‘createOrder’, which allowed database modifications without any authentication, enabling unauthorized actions such as order creation and existing data manipulation. This vulnerability was linked to:
- API3:2023 – Broken Object Property Level Authorization
- API5:2023 – Broken Function Level Authorization
- Systematic Schema Analysis:
Armed with detailed schema information, we systematically explored other vulnerabilities, confirming that the API suffered from several issues, including security misconfiguration. These vulnerabilities were directly linked to the availability of introspection:
By exposing the schema, the API inadvertently provided a roadmap for attackers to exploit these weaknesses. The ability to see every available operation and the required parameters made it significantly easier to identify and exploit these flaws.
Business Impact
While we cannot share the direct business impact in the context of the business we served, the consequences of this API vulnerability went beyond technical failures. Sensitive user data exposure, including financial and personal information, could have led to severe privacy violations, threatening compliance with regulations such as GDPR and CCPA. Additionally, unauthorized transactions and data manipulations could result in financial losses and operational disruptions, underscoring the critical need for robust API security. If these vulnerabilities were discovered and exploited by malicious attackers, it could erode customer trust and damage the company’s brand, highlighting the intangible costs associated with inadequate security measures.
Strategic Insights for Securing APIs
To prevent such breaches, organizations must adopt a proactive and comprehensive approach to API security. MerkleFence recommends the following strategies:
- Automated Testing and Penetration Testing: Conduct automated testing across the CI/CD pipeline and periodic penetration tests, as MerkleFence was commissioned to deliver in this case study.
- Disable Introspection in Production: Ensure that introspection is disabled in production environments to minimize the attack surface. Use it only in development and testing stages to aid debugging and schema verification.
- Implement Rigorous Authentication Protocols: Implement rigorous authentication protocols across all endpoints and test controls, ensuring that users have the necessary permissions to perform actions. Use multi-factor authentication where feasible.
- Deploy Continuous Monitoring: Deploy continuous monitoring and logging solutions to detect suspicious activities in real-time, enabling swift responses to potential threats.
- Implement Rate Limiting: Implement rate limiting to control the number of requests per user, protecting the system from abuse and potential denial-of-service attacks.
- Foster a Culture of Security Awareness: Educate and empower your team with a culture of security awareness within the organization, ensuring that all team members understand the importance of API security and their role in maintaining it.
Conclusion
The logistics company’s case study highlights the critical importance of proactive API security management. By understanding and mitigating risks like GraphQL introspection, organizations can protect their assets, preserve customer trust, and maintain a competitive edge in the digital age.
MerkleFence remains dedicated to advancing cybersecurity knowledge and solutions, empowering innovators to change the world securely in an increasingly interconnected world. Looking for an outstanding application security service provider? Talk to us.