What Are API Vulnerabilities?

Application Programming Interface (API) vulnerabilities are security weaknesses in an API’s code that cybercriminals can exploit. These vulnerabilities can lead to data breaches and unauthorized system access. Common API vulnerabilities include inadequate authentication and authorization, excessive data exposure and insufficient data encryption.

Continue reading to learn about the common risks associated with APIs, along with practical methods and solutions to prevent these vulnerabilities.

What is an API?

An API is a set of programming code that allows different software applications to communicate, share data and access functionalities without requiring developers or users to understand the internal implementation. For example, APIs are used to retrieve information from web services or perform actions on external systems. Think of an API as a contract between programs. Based on predefined specifications set by developers, APIs enable information retrieval and processing. Typically, APIs communicate using protocols like REST or SOAP and exchange data in formats such as JSON or XML.

6 risks associated with APIs

Some of the common risks associated with APIs include a lack of object-level and function-level authorization, weak user authentication, poor asset management, excessive data exposure and insufficient resources.

1. Lack of object-level authorization

If an API doesn’t properly validate a user’s authorization, anyone can view, change or erase data that they shouldn’t have access to in what’s known as Broken Object Level Authorization (BOLA). For example, imagine an organization’s HR team uses software to manage sensitive data, and that software provides an API for certain HR tasks. If an employee learns they can change the code in an API request, they could access sensitive data, such as payroll reports and employee information. The impact of BOLA on organizations can include employee data being exposed, violations of privacy laws and a lack of trust.

2. Lack of function-level authorization

Organizations using APIs that fail to implement the Principle of Least Privilege (PoLP) may lack proper function-level authorization. As a result, APIs could unintentionally allow unauthorized users to access data or perform actions they should not have access to. If cybercriminals gain unauthorized access to a privileged account, they could exploit this vulnerability to access sensitive data. This highlights the importance of implementing strict Role-Based Access Control (RBAC). Organizations can determine whether their API has this vulnerability if a regular user successfully performs a privileged user task without being granted that privileged access.

3. Weak user authentication

If an API cannot properly authenticate user identities, cybercriminals can exploit this vulnerability to access sensitive data. Think of this API flaw as a security guard failing to check someone’s ID before allowing them into a restricted area of a building. Without proper authentication, unauthorized users can move laterally within a network, escalate privileges or even launch attacks like ransomware, which can severely compromise an organization’s security posture.

4. Poor asset management

Poor asset management arises when an organization fails to properly document and manage the assets exposed by its APIs, including services, functions and data. The risks grow when outdated API versions are left active, unused APIs aren’t decommissioned or critical security patches are neglected. Without proper oversight, these gaps can leave the organization vulnerable to security threats.

​​5. Excessive data exposure

Excessive data exposure happens when an API response includes more information than necessary, inadvertently revealing sensitive data. Attackers can exploit this vulnerability to gather valuable information for future attacks. For example, if an API returns personal information, confidential data or system configurations that weren’t requested, it creates opportunities for misuse. This issue typically arises from inadequate data filtering during API design. When APIs don’t properly limit the data in their responses, they unintentionally expose sensitive information.

6. Insufficient resources and rate limiting

Insufficient resource management and lack of rate limiting present serious risks to APIs. This vulnerability occurs when APIs don’t impose proper restrictions on the number or size of requests or fail to manage server resources effectively. As a result, APIs may experience delays or even complete outages. Without proper rate limiting, APIs become more vulnerable to Denial-of-Service (DoS) or Distributed Denial-of-Service (DDoS) attacks, in which attackers overwhelm the server with excessive requests, preventing legitimate users from accessing the service.

How to mitigate API vulnerabilities

To mitigate a variety of API vulnerabilities, organizations should adopt the following methods.

Securely store and manage API keys

API keys are credentials for accessing APIs, and mishandling them can create serious security risks. To mitigate the chance of leakage or misuse, it’s important to implement proper lifecycle management. This includes regularly rotating keys, deactivating unused ones and limiting their access scope.

Moreover, ensure that API keys are never exposed publicly and are stored securely in encrypted vaults. It’s also important to monitor API key usage and set up a system to quickly deactivate, rotate and reissue keys if unauthorized access or suspicious activity is detected.

Implement zero-trust policies

Zero-trust policies, grounded in the principle of ‘never trust, always verify,’ continuously validate every access request. This approach ensures comprehensive monitoring and control over user, device and resource access, both inside and outside the network, making it an effective strategy for mitigating API-related threats.

One way organizations can implement zero-trust policies is by using a Privileged Access Management (PAM) solution, which strictly manages privileged account access and ensures proper API usage. By adopting PAM, organizations can monitor who accesses resources, when and under what conditions. 

Limit API usage

Implementing rate limits for API requests helps prevent unauthorized access and service disruptions. Rate limiting protects APIs from DDoS attacks and malicious high-volume requests by capping the number of requests per minute for specific IP addresses or API keys. This ensures that regular users maintain access while blocking cybercriminals from overwhelming the system.

Strengthen authentication for API access

Strengthening authentication is critical to preventing unauthorized access to APIs. Begin by implementing and enforcing a strong password policy across the organization. This policy should require complex passwords of at least 16 characters, incorporating uppercase and lowercase letters, numbers and symbols.

To further enhance security, prevent password reuse, adopt passwordless methods like passkeys and implement Multi-Factor Authentication (MFA) or biometric authentication for added protection. 

Strengthen authorization for API access

To strengthen authorization for API access, organizations must implement least privilege access. Role-Based Access Control (RBAC) is an effective way to achieve this by assigning permissions based on user roles. For example, privileged accounts like system administrators receive broader permissions, while general users are limited to only the access required for their roles. A Privileged Access Management (PAM) solution like KeeperPAM streamlines the implementation of least privilege and RBAC.

Encrypt requests and responses

Encrypting requests and responses is important for securing API communications. Unencrypted data transmitted during API interactions can be intercepted by malicious actors, potentially resulting in data breaches, tampering or credential theft.

By encrypting API communications, these risks are mitigated, and data protection is significantly enhanced. For example, implementing Secure Sockets Layer (SSL) or Transport Layer Security (TLS) ensures that data exchanged over the internet is encrypted, making it unreadable even if intercepted.

Mitigate API vulnerabilities with KeeperPAM^®

One way to mitigate API vulnerabilities is by implementing a PAM solution like KeeperPAM, a zero-trust, cloud-based solution that enforces PoLP and RBAC. KeeperPAM provides various ways to authenticate and authorize privileged accounts when managing API access, such as enabling MFA methods and biometric authentication. KeeperPAM strengthens organizations’ security postures with its zero-trust approach, enforcing strict verification for every user and system request for sensitive data. This prevents unauthorized access and mitigates the risks of credential theft, privilege escalation and other cyber threats.

Request a demo of KeeperPAM today to protect your organization’s APIs and eliminate security vulnerabilities.