API Endpoint Security: Key Benefits and Best Practices

Application programming interfaces (APIs) play a crucial role in many applications and microservices-based infrastructures. They act as intermediaries between the program’s back end and the application’s front-end logic.

92% of organizations suffer an API endpoint security breach at least once a year. Strong authentication and access mechanisms are needed to enhance API endpoint security. APIs interact and communicate with each other. And since they are commonly used, they are notoriously targeted by hackers. Exploiting API endpoint vulnerabilities can enable unauthorized access to a wealth of sensitive information. Organizations must regularly implement safety and security measures to prevent such cases. In this guide, we’ll walk you through the different API endpoint security practices so that you can be aware and stay protected.

What Is API Endpoint Security?

An API endpoint is the interface where the back end communicates with the user on the front end and other application components. It uses a shared interface and protocol. Securing this interface is crucial as a lot of sensitive information passes through it.

Compromising API endpoint security can significantly impact business operations and slow them down. The implications of neglecting API endpoint security go beyond losing the customers’ trust as organizations stake reputational and financial losses. To make matters worse, many incoming requests seem genuine but are actually disguised to be API abuse attacks.

API endpoint security involves the steps taken to protect these software applications or gateways, including securing the ways in which they interact with each other. It is a foundational component of modern web application security.

There are different components to API endpoint security which are as follows:

1. Authentication and authorization: Authentication and authorization can allow your API to authenticate and authorize incoming traffic.
2. TLS/SSL encryption: TLS/SSL encryption adds a layer of handshake-based encryption. It prevents a third party from listening and possibly reverse engineering or exploiting your API
3. Rate limiting and throttling: Rate limiting and throttling restrict the number of requests a user can make to the API endpoint, bolstering security and helping prevent distributed denial-of-service (DDoS) attacks.
4. Input validation and sanitization: Input validation and sanitization make sure the input is in the format specified by the API. It also clears the API and helps prevent rogue code from entering the API stream.
5. Regular security audits and penetration testing: Conducting regular audits of your API system using a cybersecurity company and performing penetration testing can help secure your system.
6. API gateways: API gateways provide the hosting or the endpoint for your API application. You can secure them using an endpoint security firewall like AWS API Gateway or SentinelOne Singularity.

Importance of API Endpoint Security

API endpoint security is crucial to prevent any third-party access or attacks on your API system for the following reasons:

• Developers may lack the necessary documentation to integrate third-party or internal APIs into their applications. It makes it challenging for organizations to find out how their APIs are being deployed or which ones are in current use.
• Shadow APIs are masked API endpoint security risks that may pose compliance issues. They stay hidden and these APIs are used without the approval, knowledge, or consent of the organization.
• Inadequate API monitoring and logging can create API endpoint blind spots and lead to security incidents. Organizations that rely on third-party APIs or external API services also suffer from a lack of visibility into API dependencies.
• It can prevent the leaking of sensitive user or business data and stop a third party from reverse engineering or eavesdropping on your API.
• A compromised API endpoint can affect your business and your company’s reputation because user and business data would be accessible by malicious third parties.
• Cyberattacks that result in denial of service can affect your business as well as reduce your clients’ trust in your infrastructure’s security.

Common Security Risks and Threats

The following are common security risks and threats that can affect your API endpoints:

1. Code injection: Code injection is where malicious code is injected into your API back end to harm the functioning of your system or retrieve sensitive information.
2. Broken object-level and user authentication: Unsafe coding practices can lead to API resources and access controls being insecure. Improper authorization can allow an attacker to gain unauthorized access, automate requests, and breach sensitive information. Broken user authentication exploits API vulnerabilities and impersonates users. It hijacks API sessions, steals login credentials, and causes credentials stuffing.
3. Poor asset management – Developers often lose track of their APIs and neglect API ownership. This can lead to poor asset management, causing API assets to break down over time. Some APIs may become outdated, insecure, or left undocumented as a result, thus making them vulnerable.
4. Distributed denial of service attacks: DDoS attacks are a fairly common attack where your API service sends thousands or even millions of requests at the same time. Sensitive data exposure is another cause for concern. These attacks can be difficult to pinpoint and be connected to DDoS threats. APIs fail to filter out excessive data requests and get overloaded, sometimes malfunctioning in the process.
5. API reverse engineering: API reverse engineering is the process by which the API structure and sensitive information stored within your API are retrieved when there is an unsecured connection.

What Is an API Endpoint?

API endpoints are interfaces that act as intermediaries between the back end of the system and the user. An API endpoint responds to a request by processing the user input and returning the output in a comprehensive manner to your user. There are a few safeguards that need to be in place to prevent malicious users from exploiting any vulnerabilities.

Types of API Endpoints

The following are some of the most common types of API endpoints:

1. REST APIs: REST (representational state transfer) APIs are widely used because they create an easy way to communicate with your endpoint and are relatively inexpensive to set up. REST APIs use REST-based HTTP requests to receive input information from users. The REST-based HTTP headers contain important information and metadata related to the request, which can be later captured by your API.
2. SOAP APIs: SOAP (Simple Object Access Protocol) is a type of API endpoint communication protocol that primarily uses XML to structure your API and HTTP to communicate with your endpoint. It’s more secure than plain RESTful APIs since the data is encoded in XML format.
3. GraphQL APIs: GraphQL is a modern API endpoint protocol that both receives and responds in JSON format. It’s quite secure since it doesn’t communicate over HTTP like RESTful APIs. It only responds to requested queries and doesn’t provide additional data.

How do API Attacks work?

API attacks work by targeting the vulnerabilities in your APIs and exploiting them. A malicious third party can use any of the attacks mentioned above to create a denial-of-service attack or steal your data by listening to your API endpoint.

We can broadly classify the API attacks into two types:

1. Denial of service attacks: Denial of service attacks, including distributed denial of service attacks, target the functioning of your API endpoint by sending thousands or even millions of requests at the same time, overwhelming your API service and causing a system crash and denial of service.
2. Backdoor attack: In a backdoor attack, a malicious third party gets access to your API’s sensitive information and administrative privileges. This can seriously compromise the security of your users and allow for possible reverse engineering of your API. Code injection is a common type of backdoor attack, where malicious code is sent as a parameter to the user. Another popular one is listening to unsecured API connections and retrieving sensitive data.
3. Parameter tampering: When an attacker changes the parameter between the server and the client, it is known as parameter tampering. It involves modifying critical application data and gaining unauthorized access privileges in the process.
4. Authentication hijacking: Attackers can bypass or break into various authentication methods employed by web applications. They can exploit vulnerabilities in them, compromise user accounts, and cause privacy violations.

Best Practices for API Endpoint Security

Below are some best practices you can implement when securing your API endpoints.

#1. Authentication and Authorization

Authentication and authorization ensure that every user of your API infrastructure authenticates with the API endpoint before getting access by issuing a token that users must have in advance. One of the most popular methods is the Challenge Handshake Authentication Protocol or CHAP. With CHAP, you generate an authentication token, which is then hashed and matched with the hashed tokens in the database and the API server. Successful authentication is only possible if there’s a match with the input token in the database.

This forms a basic form of authentication with more advanced layers, such as JSON web tokens (JWTs) and OAuth, which provide a complete authentication infrastructure to your system.

#2. TLS/SSL Encryption

TLS/SSL encryption secures your endpoint with a handshake-based encryption method such as SSL. This can prevent third parties from listening to your API requests and retrieving sensitive data.

You can integrate with existing Single Sign-On (SSO) providers by using OpenAuth2 with OpenID Connect. It reduces the risk of sensitive data exposure and users can verify themselves with a trusted third party by means of token exchange to get access to resources. OAuth2 can be used in both stateless and stateful modes.

#3. Rate Limiting and Throttling

Rate limiting is a security method where you set a limit on the number of requests a user can make. Similarly, throttling is a method where you restrict the number of requests a user can make in a given period (e.g., per day).

You can do this to prevent a malicious third party from mounting denial-of-service attacks on your API infrastructure. You can set it up on your back end by writing the necessary logic, or you can use something from a third-party, such as SentinelOne’s Singularity Endpoint Solution.

#4. Input Validation and Sanitization

When you send a request to an API endpoint, your input gets validated and sanitized at the API endpoint to prevent any code injection or malicious entries from being processed. This prevents possible denial-of-service or backdoor attacks on your API system.

You can secure your API endpoint using sanitization by using an external library such as nh3 for Python. It seamlessly sanitizes your input data by using the function nh3.clean (“your input data here”). You can use regex for basic input validation, or you can consider input sanitation for more advanced validation.

#5. Regular Security Audits and Penetration Testing

Regular security audits and penetration testing by a trusted cybersecurity company are a great way to do security audits. Audits test weaknesses and vulnerabilities in your system. A security auditor scans your complete API infrastructure for any possible vulnerabilities and performs penetration testing on suspected weak points to test your API infrastructure.

Regular security audits can bolster your API system’s security and performance. With an ISO 27001 cybersecurity audit, for example, a security auditor will review your organization’s security and verify that it aligns with the ISO 27001 security best practices.

#6. API Gateways

API gateways are cloud services or external API management providers that handle your API. Using one is a secure way to manage your API endpoint because the service provider takes care of a lot of the security measures for you. API gateways connect your back end with their secure API endpoint. This allows your API infrastructure to go online fast without you having to configure the complete API endpoint manually.

A popular API gateway is Amazon AWS API Gateway, and it’s widely considered to be the industry’s best.

#7. Reverse Proxy Servers

Reverse proxy servers act as intermediaries between the API endpoint and the API back end. They usually forward traffic from the endpoint and return the response generated by the API to the user or front end. This is simple to set up as it only requires a virtual server instance from your cloud provider.

You can set up the instance to act as a reverse proxy instance by using reverse proxy software such as nginx, which can also help with load balancing.

Reverse proxies therefore add a layer of security and act as a buffer between your users and your API application.

How SentinelOne Helps With API Endpoint Security

SentinelOne Singularity™ Control empowers enterprises with best-of-breed cyber security and native-suite features. It helps teams manage attack surfaces and enables them with granular, location-aware network flow controls with native firewall controls for Windows, macOS, and Linux. Users can control any Bluetooth, USB, or Bluetooth Low Energy device on Windows and Mac to reduce physical attack surfaces. You can control both in-and-outbound API network traffic and Identify any rogue endpoints that are not yet protected. Remove the uncertainty of compliance by discovering deployment gaps in your network.

Singularity™ Endpoint offers superior visibility and enterprise-wide prevention, detection, and response across entire attack surfaces. It secures your endpoints, servers, and mobile devices. You will be able to automatically identify and protect unmanaged, network-connected endpoints that are known to introduce new risks. Remediate and roll back endpoints with a single click, reduce mean times to respond, and accelerate investigations. Gather and correlate telemetry across your endpoints for holistic context into a threat using Storylines.

If you are looking for a complete API endpoint security solution, try Singularity™ Complete.

It includes:

• Powerful machine-speed malware analysis and RemoteOps forensics
• 1-click automated remediation, hybrid cloud protection, and identify infrastructure and credentials management.
• Singularity Network Discovery, a built-in agent technology that actively and passively maps your networks, delivering instant asset inventories and information about rogue devices located in your enterprise.
• Purple AI, your personal Gen AI cyber security analyst
• eBPF architecture and supports Open Cybersecurity Schema Framework (OCSF)
• The ability to centralize and transform your data into actionable threat intelligence via a unified, AI-driven Singularity™ Data Lake
• A world-class leading CNAPP that features: Kubernetes Security Posture Management (KSPM), Cloud Security Posture Management (CSPM), Cloud Workload Protection Platform (CWPP), AI-SIEM for the autonomous SOC, agentless vulnerability management, Secret Scanning, Compliance Dashboard, Offensive Security Engine™ with Verified Exploit Paths™, and more.

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Conclusion

API endpoint security solutions like SentinelOne can give a snapshot of your data flows and provide a holistic overview of your company’s security posture. Your first focus should be on testing API endpoints and mitigating any vulnerabilities associated with them. You can reduce your reliance on manual testing and use security automation to speed up threat investigations.

By protecting and securing your API endpoints, you can safeguard your web applications and deploy them securely. Good API endpoint security also protects your users and ensures that data doesn’t fall into the wrong hands.

Regular security audits can also help resolve most API flaws and weaknesses.

Stay one step ahead of your attackers and enhance your API endpoint security by using SentinelOne today!

FAQs

1. What is an API endpoint?

An endpoint is a public interface or access point where the user can interact with your API application. The API endpoint receives the user input and returns the most appropriate response as per your API function.

2. What is API endpoint security?

API Endpoint security measures are precautions taken to ensure your API Endpoint is resistant to possible data leaks and cyberattacks. This may include protecting your application against possible data injections, denial of service, and application backdoor-based attacks.

3. What are some different types of API endpoint protocols?

Some popular API Endpoint protocols are REST API, SOAP API, and GraphQL APIs. SOAP and GraphQL APIs are considered more secure protocols than REST APIs.

4. What are some common cyberattacks on API endpoints?

Some common cyberattacks on your API endpoints are but not limited to:

• Data injections: Data injections include injecting malicious code into your API endpoint, causing a denial of service, or a third party getting access to your API’s sensitive credentials.
• Distributed Denial-Of-Service attack (DDoS): DDoS attacks are when your API endpoint is made to crash by overwhelming the listener with thousands to millions of requests, eventually causing denial of service.
• Unauthorized API backdoor attack: An unauthorized backdoor attack is where a third party gets access to your API’s sensitive data and authentication keys. They can also listen to all the traffic exchanges between your users and the endpoint.