Guide Managed Security

A guide to API security: Introduction, Benefits, Challenges and Solution

What is API Security.

A guide to API security: Introduction, Benefits, Challenges and Solution

API or Application Programming Interfaces communicate information between applications. The use of APIs increased due to the fast pace of digital transformation. However, this has caused cybercriminals to exploit vulnerabilities in API to orchestrate cyber breaches.

API has continued to be one of the most highly exploited vulnerabilities that have been a low-hanging fruit for attackers worldwide for a long time. No wonder why Gartner has predicted it as one of the top attack vectors of all time and that API-based attacks like data breaches will double by 2024.

We have seen the impact of data breaches and how devastating they can be, especially for small and medium businesses. With this blog, we will explore what API security is, some common vulnerabilities found in APIs, and how API security is still relevant in 2023. We will explore how SharkStriker assists in augmenting the security of APIs.

What is API (Application Programming Interface)

API forms a critical part of applications by serving as a means of communication for services. Businesses use it to integrate additional features into applications for an improved customer experience. 

How does API  become vulnerable?

However, this often exposes their application logic and sensitive data that attackers are looking for. Since APIs are available easily over public networks, they become easy targets for attackers looking to exploit the API-related documentation to engage in denial-of-service attacks.

It makes API security a number one priority for organizations on the fifth gear to digital transformation, integrating IoT and web applications to make operations efficient and improve customer experience.

What is API security? 

 The Optus data breach was an eye-opener for security experts worldwide last year, exposing the data of millions of its users. It put a big question mark on the company’s API security.

API security as opposed to application security focuses on addressing the key areas an attacker can exploit while interacting with the API. Where application security is about safeguarding the application from malicious or anomalous intrusion, API security is a more nuanced approach to taking an attacker’s mindset into account and designing measures to protect API. 

It focuses on creating protection strategies based on the analysis of the API attack surface and securing the data that is transferred. This is where API pen testing comes into the picture. 

In this, security experts put API security to the test using real-world techniques that some of the most sophisticated cyber attackers would use. Based on this, security experts create defense strategies that are difficult for attackers to decipher. 

Why is API Security the #1 concern in 2023

API security has become a concern because of the rising attacks based on API vulnerabilities. Since APIs engage in communication that involves moving application logic, large data sets, or high-volume services, they become a primary threat vector for attackers to exploit.  

Once exploited, they can engage in API attacks like Injection Attacks, Denial of Service attacks, man-in-the-middle attacks, or insufficient logging.

Only last year, the Australian telecom giant Optus lost $1 million in an API-based attack that caused the compromise of the personal data of over 11.2 million of their customers.

Companies in the US have lost an estimated $12 billion – $23 billion in 2022 due to data breaches. There are two main reasons behind the increasing reliance on APIs and web applications:-  to increase customer experience and to make operations more efficient.

No wonder there was a 2.5x growth in web traffic since 2022. But this has made businesses vulnerable to cyber-attacks.

In one survey conducted by the ESG group,  they found that over 48% of organizations release applications into production without considering the security vulnerabilities, subjecting their network to significant risk. It proves the Gartner prediction that API-related attacks will increase from non-frequent to frequent since 2022. It is a warning sign for companies that are moving quickly.

A renowned security vendor Akamai surveyed 134 countries and found a significant spike in attacks since 2022 in the EMEA region, especially in the high-tech sector (176%) and social media (404%). Retail, technology, and finance sectors faced the most web application-based attacks comprising 70% of the total attacks. This surge in attacks specifically towards web applications is because of the need for an increased pace in digital transformation especially after the pandemic.

As per the IBM security X force report, misconfigured APIs are the reason for two-thirds of all cloud breaches.

What are some of the common vulnerabilities for APIs? 

For a good defense against API attacks, experts must gain a comprehensive understanding of the vulnerabilities associated with it. 

As of April 2023, the CISA has listed some of the most common vulnerabilities in APIs, as reported by the National Institute of Standards and Technology and the National Vulnerability Database.

OWASP or the Open Web Application Security Project is a community focused on improving software security. API has been consistently listed as one of the top 10 vulnerabilities by OWASP every year. 

They have a dedicated project called OWASP API Top 10 for the research and analysis of potent API threats and vulnerabilities. 

It assists developers with strategies and measures to address the security vulnerabilities that can lead to the compromise of their APIs.

The following are the top 10 vulnerabilities listed by OWASP for API:

Top 10 vulnerabilities listed by OWASP

1. Broken  Object Level Authorization (BOLA)

It is due to a lack of restriction (authorization) on some objects in an application. It allows the attacker to access objects that should be restricted to use, like data objects. It is one of the highly exploited vulnerabilities used to orchestrate data breaches.

2. Broken Authentication

When an application is designed without any measures to secure access, it could have this vulnerability. An attacker could engage in credential stuffing, or automated attacks, exploit any access to session IDs, or use default passwords and credentials to gain access to the application.

3. Broken Object Property Level Authorization

When an unauthorized user can access certain specific properties of an object, then the application has this vulnerability. By exploiting it, attackers can change properties, resulting in data disclosure, data loss, or manipulation by unauthorized parties.

4. Unrestricted Resource Consumption

This vulnerability is detected when there are limited or no restrictions on the usage of resources like memory, database connection pool entries, CPU, file system storage, etc. If the application does not restrict the use of resources, then the threat actor can influence the consumption,  engaging in attacks like denial of service attacks.

5. Broken Function Level Authorization

When an unauthorized user can access the administrative functions of an application through API, then it is said to have this vulnerability. Since users can access unauthorized functions, they can engage in data leakage, account takeover, or destruction of the data. 

6. Server Side Request Forgery

When a server is untested for security, an attacker can exploit its functions to modify internal resources. SSRF exploitation can lead to Denial of Service attacks, attacks against the server, or back-end systems attacks.

7. Security Misconfiguration

A vulnerability created as a result of misconfiguration is often missed out by security experts, negatively affecting the security of an API. An attacker can access sensitive data or information on API’s components and exploit misconfigured controls such as access to engage in authentication bypass attacks.

8. Lack of Protection from Automated threats

When API and web applications don’t have automated detection and response mechanisms, they are vulnerable to bot attacks. Since this is one of the most exploited vulnerabilities, experts must ensure to take automated measures against them.

9. Improper Asset Management

Regular API documentation is a must because third parties can leverage older and vulnerable versions of APIs. They can exploit unpatched systems where they host APIs. Therefore, asset inventory must be timely updated to keep track of unpatched systems.

10. Unsafe Consumption of APIs

When APIs are connected with third parties, they may suffer damage if the party has suffered a breach or an attack. It is due to a lack of verification of endpoints that interact with external or third-party APIs. It causes the exposure of sensitive data to unauthorized actors.

Some of the biggest API attacks between 2021-2023 

The Optus breach 

Around September 2022, Australian telecom giant Optus suffered an attack based on the exploitation of API vulnerability that caused the exposure of over 10 million customers.

The Twitter breach 

In August of 2022, social media giant Twitter experienced a data breach based on the exploitation of a zero-day vulnerability in their API causing a loss of over 20 million users. 

LEGO’s BrickLink 

LEGO suffered from cyber attacks in 2022 due to two API vulnerabilities in, its secondhand and vintage marketplace causing the loss of data of millions of its users. 

LinkedIn Breach  

LinkedIn suffered an API vulnerability-based data breach of over 700m users in 2021 with the exposure of personal information such as email addresses, full names, phone numbers, and addresses.

T mobile

One of the biggest API-based cyberattacks of this year (2023) was in January with the exposure of data of over 34 million customers costing the company around $350 million in a class action lawsuit.

Organizations worldwide must focus on the overall improvement of their API security by designing strategies based on the attacker’s mindset and getting their applications reviewed by cybersecurity experts.

How does SharkStriker help you with API security?

Growing digitally can become challenging when you don’t have the expertise you require to assess your API and web applications for vulnerabilities and security flaws such that you can proactively treat them. 

We have a team of threat-striking pen testers experienced in identifying and addressing the most immediate API-related vulnerabilities by pushing your API and web applications to their limits through real-world techniques. 

The following is the approach through which we ensure that your API security becomes resilient against the most sophisticated threats:


The foremost step is to create a scope identifying all the client’s requirements. That is why we work with the organizational teams to address crucial components, applications covered in the pen-testing, etc.

Accumulation of Recon and Intel 

Next, we engage in recon and intel gathering using open intelligence through publicly available information and other resources that will be useful while testing. We look for information that should not be available publicly. It includes all personal and other sensitive information.

Identification of vulnerabilities

Once the recon and intel gathering is complete, our ethical hackers use offensive techniques to hunt the applications for vulnerabilities using manual and automated tools in the network and application.


Post identification of vulnerabilities, our team of pen testers deploys non-disruptive techniques to exploit vulnerabilities and security weaknesses identified. We engage in malicious, invasive techniques to get unauthorized access to API.

Analysis and Reporting

We document all the critical findings from the test and prepare a detailed report that categorizes vulnerabilities, security weaknesses, and some measures based on best practices to treat vulnerabilities and address the underlying security loopholes.

To wrap it up

Over the years, API  has remained the single most exploited vulnerability by attackers. It is due to the quickly expanding businesses deploying IoT and web applications to increase customer experience and make business more efficient.

We have explored API security, some of the most dangerous vulnerabilities specified by OWASP, and SharkStriker’s solution to enhance API security across your IT infrastructure.

If you want to address security vulnerabilities across your APIs and applications, then SharkStriker has a range of security testing services for you. Our certified pen testers will help you take the right steps to secure your APIs such that you can scale digitally without any worries.

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