Zombie APIs are old or forgotten APIs that continue working in an organization's infrastructure without sufficient monitoring or maintenance. If organizations do not actively monitor these APIs, they continue working in the background, which results in security gaps.

These APIs increase an organization's attack surface without the knowledge of security teams. Shadow APIs stay outside of official documentation and often turn into zombie APIs when they become outdated and still keep on working.

This blog explores zombie APIs and the risks associated with them. Learn more about detecting and preventing them and remediation methods for zombie API attacks.

What are Zombie APIs?

Zombie APIs are outdated, forgotten, or abandoned APIs that remain active in an organization's infrastructure because of lack of proper management and monitoring. Although they are no longer active but can pose security and compliance risks.

Organizations do not continuously update or maintain zombie APIs, which leaves them vulnerable to attacks. Attackers exploit these APIs and bypass security measures, getting unauthorized access to sensitive information.

Zombie APIs can cause API sprawl, increase the attack surface, and make security management complex. To prevent this, organizations should remove unused and outdated APIs.

Risks of Zombie APIs

Zombie API poses threats that can reduce compliance, security, and operational efficiency. Even though they are inactive, they can still increase the risk of data breaches and regulatory violations. Here are some of the risks associated with zombie APIs:

Increased Attack Surface

Zombie APIs expand an organization's attack surface by posing hidden and undocumented entry points. These APIs are outside of standard security monitoring, so they become easy targets for unauthorized access or security breaches. Organizations should effectively monitor these APIs to detect and mitigate risks.

Unauthorized Data Exposure

Although zombie APIs are inactive, they still have access to sensitive data, like customer details, financial information, and internal corporate procedures. Without proper authentication or encryption, they become vulnerable to breaches and cause data thefts, loss of private data, financial loss, and reputational damage.

Compliance Violations

Organizations handling a sensitive data should adhere to standards such as GDPR, HIPAA, and PCI-DSS. Zombie APIs expose private data without a sufficient protection. They can put organizations at risk of non-compliance, resulting in big penalties, legal implications, and a loss of customer trust.

Outdated Security Measures

Organizations do not actively maintain or frequently update zombie APIs, making them vulnerable to common attacks. Attackers use these weaknesses to perform API attacks such as injection attacks, man-in-the-middle attacks, and unauthorized API requests.

Operational Inefficiencies

Inactive zombie APIs spread system resources and add unnecessary expense to API management. They can degrade system performance, cause connection failures, and complicate troubleshooting. Security teams should manage and remove these APIs to enhance performance and reduce operational costs.

Detecting and Preventing Zombie APIs

Using proactive measures is important to ensure a secure API environment. Here are some of the preventive measures that can help in identifying the risks before they lead to security breaches.

Continuous API Discovery

Organizations should use automated API discovery tools to find all active APIs in their infrastructure. Regular audits help identify undocumented or forgotten APIs that pose security risks. A complete API inventory will give organizations greater visibility and control and allow them to manage their API ecosystem.

Real-time API Monitoring

Real-time API monitoring is important to identify irregularities, unauthorized access attempts, and other security risks. Continuous monitoring identifies suspicious activities and checks API traffic patterns. This helps organizations to detect and reduce the risks associated with zombie APIs by implementing logging, anomaly detection, and automated response methods before any attack happens.

Strict Authentication and Authorization

Authentication tools such as OAuth and API tokens help prevent unwanted API access. The role-based access control (RBAC) ensures that only authorized users and apps use important APIs. Regularly monitor and modify access permissions and quickly remove API credentials.

API Lifecycle Management

An effective API lifecycle management method ensures that APIs are secure, updated, or removed when no longer needed. Use API development, installation, and maintenance policies to prevent zombie API attacks. Regular security reviews, proper documentation, and version control are important for maintaining the organization's data.

Security Testing and Vulnerability Scans

Regular security testing and vulnerability scanning are essential for identifying API weaknesses before attackers can exploit them. Use penetration testing and automated security scans to detect outdated APIs, misconfigurations, and potential risks. Integrating security testing in the CI/CD pipeline helps prevent threats and reduce the risk of zombie APIs.

Remediation Measures for Zombie API Attacks

A proactive approach is important to reduce zombie API risks. The following measures allow organizations to identify, remove, and secure vulnerable APIs, preventing possible breaches and unauthorized access:

Find Vulnerable APIs

Identify and remove vulnerable APIs to minimize security risks and prevent exploitation. Regularly analyze API traffic logs and use automated discovery tools to detect undocumented or outdated APIs. Continuously monitor API traffic to identify suspicious activity and remove weak APIs, reducing the risk of data exposure.

Remove Unauthorized Access and Credentials

Remove all API keys, tokens, and authentication credentials linked with the zombie API. Attackers get access to systems by using weak or unsecured credentials. Security teams should change passwords and use strong authentication techniques such as OAuth and mutual TLS to prevent them from returning. They should check access records to find any possible exploited accounts.

Apply Security Patches and Updates

Regularly update all APIs, including fixes for authentication, encryption, and input validation protocols. If an API is no longer in use, remove every reference, endpoint, and stored data from the system. This ensures that attackers don’t have any entry points for exploitation.

Analyze Activities Following Incidents

Perform a deep investigation to understand how the attack occurred, find weaknesses in API security systems, and prevent future attacks. Check security logs, unauthorized access patterns, and API traffic to know the cause of the attack. Document these findings to strengthen API security and improve threat detection mechanisms to enhance API security and prevent future attacks.

Enhance API Monitoring and Management

API monitoring and management are essential to prevent future zombie API attacks. This helps in finding suspicious activity and unauthorized access attempts. Regular risk assessments, security audits, and automated discovery tools enable organizations to safeguard and maintain all APIs.

Automate API Security Controls

Automated security solutions allow organizations to find and remove other zombie API risks. AI-powered API security platforms will help continuously monitor API traffic, find irregularities, and apply access controls. Automated deactivation techniques will remove outdated APIs without human intervention and reduce security holes.

Final Thoughts

Zombie APIs pose serious security risks, increasing the possibility of data breaches, compliance violations, and unauthorized access. Security teams should take a proactive approach, continuously monitoring API traffic, implementing strict authentication protocols, and decommissioning old APIs. A solid API security framework protects organizations from growing cyber threats.

Akto offers an advanced API security platform that helps organizations to detect, monitor, and remove zombie APIs before they become a vulnerability. Akto helps organizations improve their API security posture by providing real-time API discovery and automated security controls. Protect your APIs with Akto's cutting-edge solutions today. Schedule a demo now!

Important Links

• DAST Tools

• API Discovery Tools

• Shadow API