Before digging into a few challenges that APIs face today, let’s define the role an API plays nowadays.

## What is an API?

The Application Programming Interface (API) is like a middle man, connecting two sides; a waiter takes your order and brings you food. It is a channel that applications utilize to talk with each other. You put some information at one end, the API takes that information and gets back with a result.

Many different types of APIs exist. You can use them to build web, desktop, mobile applications, CLI tools, extensions, and much more.

Here are different types of APIs that are available to use:

-   REST API
-   GraphQL API
-   Web API
-   Browser API

<Callout
	title="Get access to Thousands of APIs"
	linkText="Sign Up"
	linkHref="https://RapidAPI.com/auth/sign-up?referral=/hub?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	RapidAPI Hub is the world's largest API hub where you can find all kinds of
	APIs according to your need.
</Callout>

## Today’s API Security Challenges

While developing APIs, API developers have to face certain challenges to protect the API from problems. By understanding and gaining more knowledge about them, API developers will be able to make better and safer APIs.

Let’s talk about those challenges:

### Upgradation of API Security

With the advance of APIs, we get to see APIs surrounding us. The more distributed our applications are, the more APIs we have and have to manage. Thus, development of APIs are taking place at a very fast pace according to growing needs.

This expandable nature of API development does not mean that a lot of care is taken for its security. Even though the number of APIs introduced in the market is increasing day by day, API security is not scaling to the same ratio.

As APIs are linked to lots of data exchange, so protecting data requires context. Traditional security is not working anymore because they don’t understand that context. This leads to different vulnerabilities.

We need an upgrade in the security system on a regular basis as more threats are encountered daily. This is one of the main issues faced by the users today.

### API’s Application Identity - API’s Key

APIs have a unique feature that identifies the application calling the API also known as an API key. These API keys are hidden inside the client application calling code, a smart developer can find them and exploit an API giving them full access to the system. This is very dangerous and can lead to various problems.

### Poorly Configured APIs

As explained earlier, an API is like a middle man connecting two sides, at times hacker sits right in the middle of the sender and the recipient. This poses a serious security threat. APIs that are not properly configured using TLS/SSL are quite prone to this sort of attack. If the transport layer communication is not secured then the whole system is at risk.

These types of attacks are very common and one of the major challenges good API developers face while developing APIs.

### Authentication & Authorization

Authentication and authorization are other common issues linked to APIs of today. Authentication differs from app to app as risks to consumer data transported through APIs are very different. You need to decide how authentication will be done based on threat modeling, manipulation and consumption of data, etc.

The issues that arise due to authentication are similar to that because of authorization. Authorization is about specific users being allowed to use specific areas of an application or specific account accessing a specific resource. Thus, certain best practices should be incorporated to avert these issues from occurring.

### Designing Correct Error Responses

Properly designed error responses will make sure that you are not giving too much information to the hackers. Knowing your data is very critical as without knowledge of what is coming in and what is going out will let your system be at risk. Thus, designing correct error messages is highly crucial and one of the challenges API developers face today.

<Callout
	title="Get access to Thousands of APIs"
	linkText="Sign Up"
	linkHref="https://RapidAPI.com/auth/sign-up?referral=/hub?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	RapidAPI Hub is the world's largest API hub where you can find all kinds of
	APIs according to your need.
</Callout>

Maham

API vulnerabilities are common and can break down your whole system if not treated, and more API breaches occur due to these vulnerabilities.

APIs Security Challenges

According to the Open Web Application Security Project (OWASP), there are ten API vulnerabilities that should be taken care of when you build an API. In this guide, let’s look at the **Broken Object Level Authorization** vulnerability.

## Broken Object Level Authorization Vulnerability

Broken Object Level Authorization (BOLA) is also known as Insecure Direct Object Reference (IDOR). It is one of the most severe and most common API vulnerabilities. Authorization flaws are often the result of improperly implemented or misconfigured authorization.

Broken object level authorization (BOLA) is somewhat similar to broken function level authorization (BFLA), but it differs from BFLA as it targets the objects that APIs interact with instead of the API’s function as in the case of BFLA.

Almost all APIs are vulnerable to BOLA. It happens when an application does not correctly confirm that the user performing the request has the required privileges to access a resource of another user.
Broken Object Level Authorization (BOLA) vulnerabilities must be identified during the code development process, through regular architecture reviews, code reviews, and evaluating API request logs as current security scanning tools can’t detect these vulnerabilities.

## Broken Object Level Authorization’s Impact

When an application includes a BOLA vulnerability, the application has a strong probability of exposing sensitive information or data to attackers. There are two types of broken object level authorizations and they are as follows:

### BOLA Type Related to User ID

In this type of BOLA, the API endpoints receive a user ID and access the user object based on this ID. Things get more complicated when one user is supposed to manage other users by design.

### BOLA Type Related to Object ID

In this type of BOLA, the API endpoint receives an ID of an object which is not a user object.
Lack of security control and human errors are the main reasons for having broken object level authorization (BOLA) vulnerabilities.

## How To Prevent It?

You can prevent broken object level authorization vulnerability in multiple ways.

-   You should extract the ID from an auth token rather than use the ID that has been sent from the client. This is one of the keys of preventing broken object level authorization.
-   You should always use an authorization mechanism to check if the logged in user has access to perform the requested action on the record in every function that uses an input from the client to access a record in the database. This will avoid broken object level authorization vulnerability from taking place.
-   By implementing a proper authorization mechanism that relies on the user policies and hierarchy can also prevent BOLA from occurring.
-   Further, by using random IDs that cannot be guessed very easily can surely avoid these issues from taking place.

<Callout
	title="Get access to Thousands of APIs"
	linkText="Sign Up"
	linkHref="https://RapidAPI.com/auth/sign-up?referral=/hub?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	RapidAPI Hub is the world's largest API hub where you can find all kinds of
	APIs according to your need.
</Callout>


APIs may have vulnerabilities like broken authentication and authorization, insufficient logging, lack of rate limiting, etc. Let’s take a look at one of them.

​​API Security – Broken Object Level Authorization Vulnerability

According to the Open Web Application Security Project (OWASP), there are ten API vulnerabilities that should be taken care of when you build an API. In this guide, let’s look at the **Injection** vulnerability.

## API Injection Vulnerability

Injection is a type of vulnerability that affects most applications and API systems. It is the underlying issue for a large number of vulnerabilities e.g. SQL injection, OS command injection, and XML injection.

It occurs when an application cannot properly distinguish between untrusted user data and code that can be HTTP request parameters, HTTP headers, and cookies. These vulnerabilities can affect API systems as well because an API is another way through which an untrusted user input can enter an application.

## Injection’s Impact

Injection can cause serious issues. A few of them are as under:

-   Database leaks
-   Authentication issues
-   Full takeover of the system
-   Denial of Service (DoS)
-   Attackers may carry out remote code execution
-   Attackers may also create new functionality etc.

## How To Prevent It?

Injections are difficult to prevent as even if the malicious user data is not used by the application right away, the untrusted data can eventually travel somewhere in the program. This untrusted data can do something bad, such as a dangerous function or an unprotected query. And this is where they cause damage to the application, its data, or its users.

Still there are certain practices that you can adopt that can aid in preventing injection vulnerability in multiple ways.

-   You should always define, limit, and enforce API outputs to prevent data leaks. This is one of the keys of preventing attacks due to injection.
-   You should always treat any input as being compromised and should filter, validate and verify every input to your API through all ways, this includes third party inputs or non direct inputs such as importing files. This will avoid injection vulnerability from taking place.
-   Trusting API consumers is a huge red flag. You should never trust your API consumers, even if they are internal. This will ensure protection against injection attacks.

<Callout
	title="Get access to Thousands of APIs"
	linkText="Sign Up"
	linkHref="https://RapidAPI.com/auth/sign-up?referral=/hub?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	RapidAPI Hub is the world's largest API hub where you can find all kinds of
	APIs according to your need.
</Callout>


APIs may have vulnerabilities like broken authentication and authorization, injection, lack of rate limiting, etc. Let’s take a look at one of them.

API Security – Injection Vulnerability

According to the Open Web Application Security Project (OWASP), there are ten API vulnerabilities that should be taken care of when you build an API. In this guide, let’s look at the **Broken Function Level Authorization** vulnerability.

## Broken Function Level Authorization Vulnerability

Authorization flaws are often the result of improperly implemented or misconfigured authorization. Broken function-level authorization is when applications fail to limit sensitive functions to the authorized users.

Broken function level authorization (BFLA) is somewhat similar to broken object level authorization (BOLA), but it differs from BOLA as it targets API’s function instead of the objects that APIs interact with as in the case of BOLA.

## Broken Function Level Authorization’s Impact

The impact of this type of vulnerability is also very severe. It can cause information leakage, getting free items, creating or deleting accounts and even full account takeover of all the accounts.

BFLA is common with enterprise applications. Attacks occur at large scale when freely available tools are used more frequently.

The API is prone to attacks if a user can access administrator only endpoints or use sensitive functionalities by simply changing the value of a method (e.g. HTML) as its function-level authorizations are broken.

## Manifestation Ways of Broken Function Level Authorization

These issues can manifest itself in many ways as under:

### Deletion

Malicious users might modify or delete other users’ posts by using different HTTP methods. This occurs when an API doesn’t place restrictions to protect against these attacks.

### Becoming Admin

Any malicious user can simply add an admin header to their requests and gain access to this admin’s functionality pretending to be an admin. Thus, broken functional level authorization can be caused by both missing access control and the bad implementation of access control.

## How To Prevent It?

You can prevent broken function level authorization vulnerability in multiple ways.

-   You should implement granular, strict access control based on the user’s session and ensure that this access control is implemented consistently regardless of a request’s method, header, and URL parameters. This is one of the keys of preventing broken function level authorization.
-   You should deny all access by default. This will avoid broken function level authorization vulnerability from taking place.
-   By only allowing operations to users belonging to the appropriate group or role can also prevent BFLA from occurring.
-   Further, by properly designing and testing authorization you can prevent this. When you will not rely on the client to enforce admin access, then also these issues can be avoided.

<Callout
	title="Get access to Thousands of APIs"
	linkText="Sign Up"
	linkHref="https://RapidAPI.com/auth/sign-up?referral=/hub?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	RapidAPI Hub is the world's largest API hub where you can find all kinds of
	APIs according to your need.
</Callout>


API Security – Broken Function Level Authorization Vulnerability

According to the Open Web Application Security Project (OWASP), there are ten API vulnerabilities that should be taken care of when you build an API. In this guide, let’s look at the **Insufficient Logging and Monitoring** vulnerability.

## Insufficient Logging and Monitoring Vulnerability

Cyber attackers usually need time to explore the network, fully exploit the system and steal the data it contains. An efficient logging and monitoring system will help detect malicious activity.

The longer an attacker is able to access the system without detection, the more likely the attacker would find a way to exploit the system, steal data, and cause extensive damage to the application and its users. Thus it’s essential to have a logging and monitoring system capable of detecting malicious activity as soon as possible.

Having an insufficient logging and monitoring system pose a serious threat as the attackers can have the access to your entire system without being noticed. This also leads to not carrying out proper investigations when something is wrong, as there is a lack of proper logging and monitoring.

## Insufficient Logging and Monitoring - Threat to Businesses

Having an online presence for your business means that you need to protect its confidential data from hackers or other security threats. Logging into a service means providing your personal data that you are not comfortable sharing with the world.

Protecting logs from various attackers should be the primary objective of any business having an online presence. Thus, having a sufficient logging will make sure that the attackers don’t exploit the confidential data for its benefit.

If, you do not have a sufficient logging system and an attack occurs, then there is no way of tracing the attacker’s call.

## Various Insufficient Logging and Monitoring Threats

Various threats associated with insufficient logging and monitoring are as under:

### Brute Force Phishing & DDoS Attacks

Attacks supported by bots put together other attacks including Brute Force Phishing and Distributed Denial of Service (DDoS). These attacks help injection of malware into a system and then they can manipulate the entire system to their use in different ways.

In the absence of proper logging of event data, these attacks are almost impossible to detect or analyze. Thus, an efficient logging and monitoring system is the first line of defense against these botnet attacks.

### Domain Name Service (DNS) Attacks

DNS attacks may include cache poisoning, DNS tunneling, domain lock-up attack, etc. If DNS based events are not logged and monitored, administrators won’t know the types of machines attackers interact with.

### Malware traffic, Ransomware attacks & Advanced Persistent Threats

Insufficient monitoring and log management in many cases result in untraceable user behavior patterns, allowing imposters or malicious insiders to compromise the system at a much deeper level.

These types of internal threats suspicious activities often go unchecked and are extremely critical to organisations. Thus, sufficient monitoring will prevent this from taking place.

## How To Prevent It?

You can prevent logging and monitoring attacks in multiple ways.

-   To make sure that logging and monitoring issues does not take place, you should authenticate access to logs.
-   You should automate monitoring and alerts for log events. This will ensure that whenever an attacker tries to log in the system you can be alerted and can take actions to avoid the malicious activity from occurring.
-   Further always perform penetration tests to identify gaps in incident monitoring and reporting and having a recovery plan or strategy developed for rainy days.

<Callout
	title="Get access to Thousands of APIs"
	linkText="Sign Up"
	linkHref="https://RapidAPI.com/auth/sign-up?referral=/hub?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	RapidAPI Hub is the world's largest API hub where you can find all kinds of
	APIs according to your need.
</Callout>


APIs may have vulnerabilities like broken authentication, insufficient logging & monitoring, lack of rate limiting, etc. Let’s take a look at one of them.


API Security – Insufficient Logging & Monitoring Vulnerability

APIs need to be secure as they play a significant role in moving the data between two sides. And when the data is concerned, the API developer can often integrate excessive data exposure, a security vulnerability. Let’s take a quick look at it.

## Excessive Data Exposure

This vulnerability is highlighted by the Open Web Application Security Project (OWASP). The API developer sends more data than required to the client. The client-side has to filter the information to show it to the user, thus leaving a lot of unused data. This remaining data can fall prey to potential data leaks.

The man-in-the-middle is the most common attack that can exploit this information as the data can be intercepted by the unwanted personnel when it is in transit. The data can later be used to perform different actions on the website. It can be sold to the highest bidder.

## Prevention techniques

There are a few ways you can avoid all excessive data exposure. Let’s look at them.

### Data filtering

Instead of relying on the client-side to filter the data, this operation should be performed on the server before sending the data. The client-side should only take the data and render it on the screen.

### Send only the Necessary Information

Another thing that you can do is to ensure only the data the client has requested is sent to them. You are not sending any unnecessary information.

### Categorizing Data

To ensure that you are not sending sensitive data, you can also categorize your data as admin, personal, or sensitive information.


Saad Irfan

In Excessive Data Exposure Vulnerability, the API sends more data than required to the client. In this piece, let’s look at it and some prevention measures.

API Security: Excessive Data Exposure Vulnerability

According to the Open Web Application Security Project (OWASP), there are ten API vulnerabilities that should be taken care of when you build an API. In this guide, let’s look at the **Lack of Resources & Rate Limiting** vulnerability.

## Lack of Resources & Rate Limiting

When the API does not limit the number or frequency of requests from a particular API client, the client can make many API calls per second or request hundreds or thousands of data records at once. In this scenario, the server will still try to fulfill these requests. This causes lack of resources and rate limiting issues.

This vulnerability allows attackers to launch DoS attacks and can overall affect the API server’s performance. 

When the server receives too many requests at a time, this hampers its ability to process requests and make the service slow or not available for other users. Lack of rate limiting can also lead to removing sensitive data faster if an API endpoint is leaking information by the attackers.

## How To Prevent It?

You can prevent lack of resources and rate limiting in multiple ways. 

- To make sure that lack of resources and rate limiting issues does not take place, you should make sure that the client can only make a certain amount of requests over a certain period. This will limit the number of requests from affecting the API server’s performance.
- You should verify on the client and server side that the request body and response are not too big. This will in return help save from the issue.
- Further adding checks on compression ratios will also prevent it from occurring.

<Callout
    title="Get access to Thousands of APIs"
    linkText="Sign Up"
    linkHref="https://RapidAPI.com/auth/sign-up?referral=/hub?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
    RapidAPI Hub is the world's largest API hub where you can find all kinds of
    APIs according to your need.
</Callout>






​​API Security – Lack of Resources & Rate Limiting Vulnerability

According to the Open Web Application Security Project (OWASP), there are ten API vulnerabilities that should be taken care of when you build an API. In this guide, let’s look at the **Security Misconfiguration** vulnerability.

## Security Misconfiguration

Attackers can exploit misconfiguration in API servers. Security breaches are facilitated when API resources, application infrastructure, and transport protocols include misconfigurations.
These misconfigurations pose a serious threat that attackers can take advantage of. 

Security misconfigurations include unnecessary HTTP methods, data leakage, usage of default configuration with no or weak authentication, misconfigured HTTP headers and no enforcement of HTTPS.

Further, data corruption through unsanitized inputs, open cloud storage and cross-origin source sharing is a reason for this vulnerability to occur. If these issues are not taken care of then the overall API’s security is at stake.

## How To Prevent It?

You can prevent security misconfigurations in multiple ways. 

- As security breaches may occur when API resources, application infrastructure, etc include misconfigurations. So, to avoid this you should automate locating configuration flaws.
- By disabling unnecessary features this can be avoided too and will in return protect from the misconfiguration vulnerability.
- By establishing repeatable hardening and patching processes and also, by restricting administrative access, will prevent this from taking place.

<Callout
    title="Get access to Thousands of APIs"
    linkText="Sign Up"
    linkHref="https://RapidAPI.com/auth/sign-up?referral=/hub?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
    RapidAPI Hub is the world's largest API hub where you can find all kinds of
    APIs according to your need.
</Callout>




APIs may have vulnerabilities like broken authentication and authorization, misconfiguration, lack of rate limiting, etc. Let’s take a look at one of them.

API Security – Misconfiguration Vulnerability

According to the Open Web Application Security Project (OWASP), there are ten API vulnerabilities that should be taken care of when you build an API. In this guide, let’s look at the **Improper Assets Management** vulnerability.

## Improper Assets Management

Most vulnerabilities on the OWASP API top ten revolves around coding flaws. Contrary to this, improper assets management is not a coding mistake, but a human or management problem. This vulnerability allows older APIs to be in place long after they should have been replaced by newer, more secure versions.

Attackers find non-production versions of the API that are not as well secured as the production API. These versions are used by them to launch their attacks.

When APIs that are still in development before they are fully hardened against threats are exposed to the production environment, then there is a high chance of this vulnerability to take place. If these issues are not taken care of then the overall API’s security is compromised.

## How To Prevent It?

You can prevent improper assets management in multiple ways.

-  To prevent the attackers from finding the non-production versions of the API to launch attacks, you need to control access to production data, and segregate access to production and non-production data.
-  By deleting APIs which aren’t being used. There is no reason to keep them online and accessible either internally or externally if they are no longer in use and implement additional external controls e.g. API firewall etc.
-  Improper asset management’s vulnerability can be addressed by having an API rollout strategy with strong documentation and inventories.

<Callout
	title="Get access to Thousands of APIs"
	linkText="Sign Up"
	linkHref="https://RapidAPI.com/auth/sign-up?referral=/hub?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	RapidAPI Hub is the world's largest API hub where you can find all kinds of
	APIs according to your need.
</Callout>


APIs may have vulnerabilities like broken authentication and authorization, improper assets management, lack of rate limiting, etc. Let’s take a look at one of them..

API Security – Improper Assets Management Vulnerability

According to the Open Web Application Security Project (OWASP), there are ten API vulnerabilities that should be taken care of when you build an API. In this guide, let’s look at the **Broken User Authentication** vulnerability.

## API Broken User Authentication

Incorrectly applied authentication mechanisms pose a serious threat that attackers can take advantage of. Weak authentication allows hackers to break into internal systems. Authentication is broken when attackers can compromise passwords, users' account information, etc., to know users' identities.

Broken user authentication occurs because of the single API key for all apps when there is no idea where traffic is coming from and there is no way to pinpoint anomalies. In this way, the overall API’s security is compromised.

Further, authorization flaws that make the endpoint susceptible to credential stuffing and brute-force attacks is another common misconfiguration that lead to broken user authentication. Also, weak or poorly managed passwords are a reason for this vulnerability.

## How To Prevent It?

You can prevent API broken user authentication in multiple ways.

-   As described earlier, it occurs due to weak authentication. So, you should check all possible ways to authenticate to all APIs.
-   You should use APIs for password reset and one-time links that will allow users to authenticate. This will in return protect from the authentication vulnerability.
-   You should use token generation, password storage, and multi-factor authentication (MFA). This will again help in not compromising the API’s security.

<Callout
	title="Get access to Thousands of APIs"
	linkText="Sign Up"
	linkHref="https://RapidAPI.com/auth/sign-up?referral=/hub?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	RapidAPI Hub is the world's largest API hub where you can find all kinds of
	APIs according to your need.
</Callout>


API Security – Broken User Authentication Vulnerability

According to the Open Web Application Security Project (OWASP), there are ten API vulnerabilities that should be taken care of when you build an API. In this piece, let’s look at one of them.

## API Mass Assignment

It is a severe API threat that arises when you save the request body as it is on the server instead of getting values from it one by one. It allows the user to initialize or overwrite server-side variables that the application does not intend.

Generally, it is easy to spread an object to create its copy and save it in the database, but this practice should be avoided. It is because if someone figures out the request payload, they can send more key values that can alter their presence on the web application.

A more appropriate way to do it would be to create a new object on the server-side by extracting only the fields you need from the request body and saving that object.

## How To Prevent It?

You can prevent API mass assignment in multiple ways.

-   As described earlier, you should not explicitly bind incoming data and internet objects because the user can send more data than required.
-   Write a schema to define all the types and patterns you will accept in the request and then implement it on runtime.
-   You should set the read-only property to true for all the fields that can be retrieved from the API request body but should not be modified by the user.
-   You should also explicitly define the request body and query parameters you are expecting from an API request.


It is a severe API threat that arises when you save the request body as it is on the server instead of getting values from it one by one. In this piece, let’s take a quick look at it.

A brief guide on API Mass Assignment Vulnerability

Let’s talk about five basic practices to secure a REST API. You can also learn about all the best practices for REST API security [in this guide](https://RapidAPI.com/guides/practices-rest-security?utm_source=RapidAPI.com/guides&amp;utm_medium=DevRel&amp;utm_campaign=DevRel).

<Callout
	title="Get access to Thousands of APIs"
	linkText="Sign Up"
	linkHref="https://RapidAPI.com/auth/sign-up?referral=/hub?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	RapidAPI Hub is the world's largest API hub where you can find all kinds of
	APIs according to your need.
</Callout>


## Hashed Passwords

Passwords should always be hashed to secure the system even if it is under hacking attempts. This is one of the most common and easiest ways of protecting the REST API.

## Never Use Easily Exploitable URLs

Easily exploitable URLs include usernames, passwords, API keys, etc. All this information should not appear in the URL as it leads to hacking attempts.

## Using OAuth2

OAuth2 is a standard that explains how a third-party application can access data from an application on behalf of a user. It is a more general framework built primarily for authorization. This should be implemented to protect the REST API.

## Avoid Complex Security Techniques

Secure the REST APIs by using simpler techniques. The more you dig into the complex ones, you are more likely to leave holes that affect its overall security.

## Always Use Transport Layer Security (TLS)

TLS should be enforced as a standard for all APIs. It secures the information the API and the user sends by encrypting the messages in transit. TLS enabled websites URL start with `https://`. This way you will be able to secure your RESTful APIs.


REST APIs allow you to create, read, update and delete operations between a client and a server. There are a number of ways to secure REST APIs.

Five Basic Practices For REST API Security

Several API threats exist. The API injection provides a great deal of risk for the database the API is communicating with for performing CRUD operations. All this comes under API security, and it should not be taken lightly.

## API Injection

When the user sends malicious code (most of the time database query) with the API request, they execute an API injection. The code is sent as part of the query parameter or request body depending on the underlying API code.

The API injection can be a command injection attack. It means the API will bring a system command to the server. The command, when executed, can delete user directories or even the entire site from the server. The most common example is when you want to view the file you have uploaded yourself. To retrieve the file, the API will take the file's id with it. If the user sends the malicious command with the API request, it will execute it on the server.

## Preventing API Injections

The main reason why the API is vulnerable to such security loopholes is that the web app developer and the API developer both did not sanitize the input before it reached the API call code. So ensure that you do input validation in your application.

You can also prevent API injection via escaping special characters. It means you encode special characters and change their meaning, so they are treated as data rather than special characters. This way, the interpreter will know that this data is not for execution.


When the user sends malicious code (most of the time database query) with the API request, they execute an API injection. In this piece, let’s take a look at it and how you can prevent it from happening.

What are API Injections and how to prevent them?

## REST APIs

REST APIs allow you to perform CRUD (create, read, update, and delete) operations between a client and a server. It is the most common type of API, and almost [80%](https://www.programmableweb.com/news/json-clearly-king-api-data-formats-2020/research/2020/04/03) of all public APIs are REST. Many people even confuse the term API with the REST API. Therefore, it is crucial to ensure that REST APIs follow the security standards to avoid vulnerabilities.

## Best Practices for REST API Security

Here are some good practices to ensure a robust and secure REST API implementation.

### Implement Authentication

You should always be aware of who is calling your APIs. Validating the clients of an API to identify if they are who they claim to be is called API authentication. OAuth 2.0 (Open Authorization) is a standard developed to allow a user access to resources from a third-party application. It is an authorization protocol designed only to grant access to resources, and it works by using access tokens.

The access token is information that provides authorization to access resources on behalf of the user. Usually, we can use the JSON Web Token (JWT) format for the access token. Implementing an Auth standard like OAuth 2.0 ensures proper authentication because the user's identity is validated, unlike API keys, where only the application's identity is validated.

### Use TLS (HTTPS)

API keys and authentication parameters may be compromised during server-client communication. Therefore, it is critical to use Transport layer Security(TLS) which protects the information by encrypting it. A quick way to check TLS availability is to see if the URL starts with `HTTPS`. If it does, then it means that TLS is enabled. SSL, the predecessor of TLS, can also be used for the same purpose.

### Validate API Parameters

REST APIs use path, query, request body, and header parameters to pass information from the client to the server. These parameters must be validated to ensure that they don't comprise security. We can do it by establishing a schema for incoming parameters and validating the parameters against the schema.

### Rate Limiting

A large number of requests within a short time are computationally expensive and may render your API unresponsive. Luckily, we can limit the number of requests a client can make to the API in a specific time window. This process is called rate limiting. Rate limits are crucial to prevent excessive use and brute force attacks like DDoS.

### Implement Content Types

Implement content-type checking by defining the allowed content types in your REST API using the `Content-Type` and `Accept` headers. The `Content-Type` header specifies the type of data sent to the server. The `Accept` header specifies the type of data the client expects to receive from the server. As a result, all requests that do not correct types will be rejected to prevent potential attacks.

### Restrict Access to Resources

Restrict non-permitted HTTP methods to avoid unauthorized access to resources. We can do this by specifying the allowed HTTP methods like `GET`, `POST`, etc., and restricting any request that uses other HTTP methods.

### Use Pagination

If the API returns large amounts of data, it is always good to use pagination. It allows the client to limit the number of resources they can access in a single request. We can also establish pagination limits to define the maximum number of resources a client can access in a single request. If we don't use pagination, a request for all the resources in an extensive collection may slow down or crash the server.

## Final Note

That's pretty much it. We hope that this guide will help you keep your REST API secure and performant.


Ahmad Bilal

With the rise of APIs, API security demands more focus than ever. Let’s discuss some practices that can help secure REST APIs.

Best Practices for REST API Security

## GraphQL APIs

GraphQL, a query language, is an API standard for data query and manipulation. GraphQL queries enable declarative data fetching and expose only a single endpoint that you can use to get data.

To understand how GraphQl works, think of it as a graph. When requested, it exposes a single "edge" of the graph, which is an endpoint.

## Best Practices

Here are a few good practices to ensure a robust GraphQL API implementation.

### Use Depth Limiting

As mentioned earlier, GraphQL allows you to specify the exact data you want by nesting the fields. While this is an advantage, it can also be a bad thing. Consider the following query that fetches the posts of a user:

```graphql
{
  user(id: '12') {
    posts {
      title
    }
  }
}
```

An attacker can use such nesting to create complex cyclical queries like this:

```graphql
# Depth : 7+
query largeNestedQuery {
  user(id: "12") {
    posts {
      user {
        posts {
          user {
            posts {
              user {
                  # and more..
              }
            }
          }
        }
      }
    }
  }
}
```

As you can see, this query is several levels deep, and it can create a big loop. Queries like this are computationally expensive and may render your API unresponsive. Thus, to protect the API from such queries, you should limit the nesting depth.

You can set a specific number (e.g., 7) to limit the nesting depth for your API. Then, if a query has more than seven levels of nesting, it will be rejected.

### Use Timeout

Depth limiting is not always practical, so another thing you can do is to set a time limit for the queries. If a query takes longer than the time limit, a timeout will occur and reject it. So, a GraphQL server must implement a timeout to secure the API from slow and malicious queries.

### Rate Limiting

Other than limiting the time and depth of the queries, you can also limit the number of queries allowed in a specific time window. This process is called rate limiting, but unlike REST APIs it is not very straightforward for GraphQL APIs.

The reason is that in GraphQL, you can have several requests inside a single query. So, a single GraphQL query can have an equal cost as a hundred REST calls. Such a query will follow your rate limit (such as five requests per minute), but it will be very costly for your server.

So, GraphQL rate limiting is a bit more complicated. For effective rate limiting, you can use a cost-based algorithm to apply the rate limit as GitHub does with their [GraphQL API](https://docs.github.com/en/graphql/overview/resource-limitations#rate-limit).

### Do Cost Analysis of Queries

As the name suggests, cost analysis estimates the cost of a query. It restricts a query if it is computationally expensive. There are different ways to determine the query cost, and they depend on the API in question.

### Use Pagination

If you are fetching large amounts of data, it is always good to use pagination. It limits the number of resources the clients can access in a single request. If we don't use pagination, a query for all the resources in a big collection may slow down or crash your server. You can set pagination limits to avoid this. For example, if you have a pagination limit of 100, the first query will return an error:

```graphql
InvalidQuery {
  posts(first: 500) {
    title
    body
  }
}

ValidQuery {
  posts(first: 100) {
    title
    body
  }
}
```

### Protect Against Batch Requests

[GraphQL Aliases](https://rapidapi.com/guides/graphql-aliases-variables#aliases) allow you to query the same field with different arguments inside a single query. Without aliases, the query will return an error. This is called batching, and you can try it out here:

<GraphQLClient type="aliases" />

It is a great feature, but it can be dangerous as well. Clients may use excessive batch requests to intentionally slow down the API or scrape data from the API. Take a look at the following query, which uses aliases to query all the data of `users` in a single request:

```graphql
query BadQuery {
  alias1: users { subField1 subField2 ...}
  alias2: users { subField1 subField2 ...}
  ...
  alias100: users { subField1 subField2 ...}
  ...
  alias1000: users { subField1 subField2 ...}
  ...
}
```

We can avoid this vulnerability by implementing effective rate and cost limits.

## Final Note

That's pretty much it. We hope that this guide will help you keep your GraphQL API secure and performant.


GraphQL APIs are a tad different from conventional REST APIs, so let’s discuss some practices specifically for GraphQL APIs.

Best Practices for GraphQL API Security

## Security APIs

A couple of decades ago, adding new features to your web application was only possible through coding the entire feature yourself and integrating it into the application. The rise of APIs has made this process much more straightforward, and today there are APIs serving all kinds of functions.

Implementing security features from scratch is not an easy feat, which is why we mentioned five security APIs in our [previous guide](https://RapidAPI.com/guides/five-security-apis) and this guide would add five more notable security-related APIs. You can easily integrate them into your applications to increase their security capabilities.

### 1. Twilio Verify Phone Number API

[Twilio Verify Phone Number API](https://RapidAPI.com/twilio/api/twilio-verify-phone-number/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel) is an excellent tool for adding phone-based verification and two-factor authentication to your application by sending codes via text or voice.

The API works using elementary logic. The developers embed the API in their apps or websites. When a new user is signing up for the website or app’s services, the registration form requires that they input their mobile number. The API collects the mobile number and sends a verification code to the provided number. Then, the user enters this code to complete the registration process.

<Callout
	title="Connect to the API"
	linkText="Connect"
	linkHref="https://RapidAPI.com/twilio/api/twilio-verify-phone-number/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	Check out the API and start using it.
</Callout>

### 2. IP Geolocation and Threat Detection API

[IP Geolocation and Threat Detection API](https://RapidAPI.com/ipregistry3-ipregistry/api/ip-geolocation-and-threat-detection/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel) is an efficient API that you can add to your application to pinpoint your users' locations and get their location data. From a security point of view, it helps you implement geo-restrictions and compliances and prevent fraud.

<Callout
	title="Connect to the API"
	linkText="Connect"
	linkHref="https://RapidAPI.com/ipregistry3-ipregistry/api/ip-geolocation-and-threat-detection/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	Check out the API and start using it.
</Callout>

### 3. Easy Email Validation API

[Easy Email Validation API](https://RapidAPI.com/principalapis/api/easy-email-validation/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel) provides Email Validation services and allows you to check the validity of Emails by verifying their domains. It also checks for valid formats and disposable emails, which is very helpful.

<Callout
	title="Connect to the API"
	linkText="Connect"
	linkHref="https://RapidAPI.com/principalapis/api/easy-email-validation/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	Check out the API and start using it.
</Callout>

### 4. BreachDirectory API

[BreachDirectory API](https://RapidAPI.com/rohan-patra/api/breachdirectory/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel) provides a resource to check and avoid compromised accounts. It allows you to check whether an email, username, password, or phone number was affected by a data breach.

<Callout
	title="Connect to the API"
	linkText="Connect"
	linkHref="https://RapidAPI.com/rohan-patra/api/breachdirectory/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	Check out the API and start using it.
</Callout>

### 5. Ephemeral Proxies API

[Ephemeral Proxies](https://RapidAPI.com/rpi4gx/api/ephemeral-proxies/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel) offers proxy capabilities and lets you establish a stable proxy connection.

<Callout
	title="Connect to the API"
	linkText="Connect"
	linkHref="https://RapidAPI.com/rpi4gx/api/ephemeral-proxies/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	Check out the API and start using it.
</Callout>


API is a channel that applications utilize to talk with each other. You put some information at one end, the API takes that information and gets back with a result. This guide will focus on those APIs that provide security-related features.

Five More APIs That Add Security Capabilities To Your Application

Let's take a look at API authentication.

## API Authentication

You should always be aware of who is calling your APIs. Validating the clients of an API to identify if they are who they claim to be is called API authentication. Authentication allows you to restrict access to your API endpoint, which is essential for securing your API.

Moreover, authentication allows you to limit access to the API endpoints based on the requirements. We can also implement rate limits and audit logs through API authentication.

## Best Practices

Here are some good practices to ensure robust API authentication.

## Use API Keys

A suitable way to control access to your APIs is to use secret keys. With API key authentication, you can verify the identity of each app or user and mitigate the risks of unauthorized access. Moreover, this information can be used to maintain a log and determine the extent of resources accessed.

For example, [RapidAPI Hub](https://RapidAPI.com/hub?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel) (which hosts thousands of public APIs) generates secret keys for implementing API Authentication that look like this.

![Secret API Key](https://raw.githubusercontent.com/RapidAPI/DevRel-Stack-Data/production/guides/posts/practices-api-authentication/images/key.png)

## Store API Keys Securely

API keys are very convenient to use, and they allow you to limit access to the API service. However, they do not identify the client's identity as anyone with the API key can access your service. Therefore, the client and the API provider must keep API keys secure to avoid them being compromised. A common mistake is embedding the API key in the code, which can be easily discovered. Instead, make a habit of using environment variables and secrets to store API keys.

## Implement an Auth Standard

OAuth 2.0 (Open Authorization) is a standard developed to allow a user access to resources from a third-party application. It is an authorization protocol designed only to grant access to resources, and it works by using access tokens.

The access token is information that provides authorization to access resources on behalf of the user. Usually, the JSON Web Token (JWT) format is used for the access token. Implementing an Auth standard like OAuth 2.0 ensures proper authentication because the user's identity is validated, unlike API keys, where only the application's identity is validated.

## Use TLS

API keys and authentication parameters may be compromised during server-client communication. Therefore, it is critical to use Transport layer Security(TLS) which protects the information by encrypting it. A quick way to check TLS availability is to see if the URL starts with `https`. If it does, then it means that TLS is enabled.

## Final Note

That's pretty much it. We hope that this guide will help you keep the Authentication of your API in check.


With the rise of APIs, API security demands more focus than ever. Authentication determines the client’s identity who is sending the request and ensures that your API is properly secured. This guide will highlight some good practices of API Authentication.

Best Practices of API Authentication

## Security APIs

A couple decades ago, adding new features to your web application was only possible through coding the entire feature yourself and integrating it in the application. The rise of APIs has made this process much simpler, and today there are APIs serving all kinds of functions.

Implementing security features from scratch is not an easy feat, which is why we have hand picked some of the popular and notable security related APIs out there. You can easily integrate them in your applications to increase their security capabilities.

### 1. IP Geolocation API

[IP Geolocation API](https://rapidapi.com/natkapral/api/ip-geo-location/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel) looks up IP addresses of visitors and provides their geolocation information. The information includes country, city, latitude, longitude, timezone, asn, currency and other security data.

<Callout
	title="Connect to the API"
	linkText="Connect"
	linkHref="https://rapidapi.com/natkapral/api/ip-geo-location/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	Connect to the API and start using it.
</Callout>

### 2. Telize API

[Telize API](https://rapidapi.com/fcambus/api/telize/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel) is another efficient API that you can add in your application to get the visitors' IP addresses and thier location data. From a security point of view, it helps you implement geo-restrictions and prevent frauds.

<Callout
	title="Connect to the API"
	linkText="Connect"
	linkHref="https://rapidapi.com/fcambus/api/telize/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	Connect to the API and start using it.
</Callout>

### 3. Telesign API

[Telesign API](https://rapidapi.com/telesign/api/telesign-sms-verify/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel) is a great tool for adding phone-based verification and two-factor authentication to your application.

The API works using elementary logic. The developers embed the API in their apps or websites. When a new user is signing up for the website or app’s services, the registration form requires that they input their mobile number. The API collects the mobile number and sends a verification code to the number that is provided. Then, the user enters this code to complete the registration process.

<Callout
	title="Connect to the API"
	linkText="Connect"
	linkHref="https://rapidapi.com/telesign/api/telesign-sms-verify/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	Connect to the API and start using it.
</Callout>

### 4. ZeroBounce API

[ZeroBounce API](https://rapidapi.com/leeann/api/zerobounce1/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel) is a comprehensive Email Validation service that allows you to check the validity of Emails by verifying their domains. It also has some intersting features like suggestions for fixing an email typo.

<Callout
	title="Connect to the API"
	linkText="Connect"
	linkHref="https://rapidapi.com/leeann/api/zerobounce1/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	Connect to the API and start using it.
</Callout>

### 5. Spam Check API

[Spam Check API](https://rapidapi.com/security-bull-security-bull-default/api/spam-check/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel) does exactly what it says; it checks text contents for potential spam through an ML based system.

<Callout
	title="Connect to the API"
	linkText="Connect"
	linkHref="https://rapidapi.com/security-bull-security-bull-default/api/spam-check/?utm_source=RapidAPI.com/guides&utm_medium=DevRel&utm_campaign=DevRel"
>
	Connect to the API and start using it.
</Callout>


API is a channel that applications utilize to talk with each other. You put some information at one end, the API takes that information and gets back with a result. In this guide, we will focus on those APIs that provide security related features.
authors:

API Security

APIs Security Challenges

API vulnerabilities are common and can break down your whole system if not treated, and more API breaches occur due to these vulnerabilities.

​​API Security – Broken Object Level Authorization Vulnerability

APIs may have vulnerabilities like broken authentication and authorization, insufficient logging, lack of rate limiting, etc. Let’s take a look at one of them.

API Security – Injection Vulnerability

APIs may have vulnerabilities like broken authentication and authorization, injection, lack of rate limiting, etc. Let’s take a look at one of them.

API Security – Broken Function Level Authorization Vulnerability

APIs may have vulnerabilities like broken authentication and authorization, insufficient logging, lack of rate limiting, etc. Let’s take a look at one of them.

API Security – Insufficient Logging & Monitoring Vulnerability

APIs may have vulnerabilities like broken authentication, insufficient logging & monitoring, lack of rate limiting, etc. Let’s take a look at one of them.

API Security: Excessive Data Exposure Vulnerability

In Excessive Data Exposure Vulnerability, the API sends more data than required to the client. In this piece, let’s look at it and some prevention measures.

​​API Security – Lack of Resources & Rate Limiting Vulnerability

APIs may have vulnerabilities like broken authentication and authorization, insufficient logging, lack of rate limiting, etc. Let’s take a look at one of them.

API Security – Misconfiguration Vulnerability

APIs may have vulnerabilities like broken authentication and authorization, misconfiguration, lack of rate limiting, etc. Let’s take a look at one of them.

API Security – Improper Assets Management Vulnerability

APIs may have vulnerabilities like broken authentication and authorization, improper assets management, lack of rate limiting, etc. Let’s take a look at one of them..

API Security – Broken User Authentication Vulnerability

APIs may have vulnerabilities like broken authentication and authorization, insufficient logging, lack of rate limiting, etc. Let’s take a look at one of them.

API Security – Broken Object Level Authorization Vulnerability

API Security – Lack of Resources & Rate Limiting Vulnerability