APIs (Application Programming Interfaces) have become the gateway to enable software programs to communicate with each other. They operate like digital bridges that pass information between different systems. APIs play a crucial role in modern software by enabling apps to communicate and work together. API security protects these data connections from unauthorized access and attacks. A good API security framework protects sensitive data, blocks malicious requests, and allows only those who should have access to the API to use it. With companies moving more of their key services online, it makes sense that this protection matters even more today. This blog explains what exactly API security risks are.
We will discuss simple security concepts, familiar threats attackers use, and how to prevent these attacks.
What is API Security?
API security refers to the process of using various methods/devices to protect an organization’s API and its data from various security threats. This entails identifying who has authorized access to the API, securing data in transit between systems, and ensuring requests issued to the API are secure.
Why is API Security Essential?
API security secures sensitive user information and organizational systems. As long as APIs are secure, they don’t allow attackers to be able to steal data or access systems. When APIs function securely, trust in business remains intact. A lot of compliance standards also state that APIs need to be secure, or organizations owning them will be fined.
APIs connect business systems that handle money, users, and company secrets. With APIs not having good security, attackers can get in and take this data. It costs organizations money, breaks customer trust, and creates legal issues. API attacks continue to rise annually, which makes securing these endpoints even more critical.
14 API Security Risks and Mitigations
APIs are exposed to numerous security threats on a daily basis. Those risks vary from basic bugs in the code to more elaborate attacks. Understanding these threats makes it easier for security teams to develop appropriate defenses. Let us see some of the most common API security vulnerabilities and how to remedy them.
1. Broken Access Control
Broken access control allows users to read or modify resources outside the scope of their intended access. The simplest example is that an attacker may modify the ID in the URL and retrieve another user’s data. This happens when APIs do not validate whether the user who is logged in has permission to view or update requested data. On some APIs, attackers can promote their own role or change settings without access checks at all.
To fix broken access control, organizations should begin by checking user roles for every API request. Define who should see what data, and reference the owner of the dataset to ensure that it is fine to be displayed. Use matching tokens aligned with precise user rights and conduct consistent security audits to find access control issues.
2. Broken Authentication
When APIs do not validate user identity strongly enough, the application runs into broken authentication. Weak passwords or never-expire old login tokens are sometimes acceptable on APIs. If authentication does not work properly, attackers can brute force weak passwords to bypass existing authentication mechanisms to exfiltrate user data.
Organizations should implement strong password policies and a two-step login before key events to increase authentication. Also, companies should implement login tokens that expire after a certain time and lock users out after repeated failed password attempts. Apart from that, validate login tokens on every API request and monitor abnormal login patterns that may indicate attacks.
3. Data Exposure
Data Exposure is when an organization’s APIs return more data than necessary. This tends to cover any database fields, debugging data, or system details in error messages. Organizations can face issues when only specific fields are requested, and instead of returning what was expected in the response object, it returns back full data objects. Attackers use this additional information for reconnaissance and further attacks.
To avoid exposing sensitive data, organizations should make a schema of what each API should return. Responses should be trimmed of unnecessary details, and error messages should contain no system info. Implement scrubbing of sensitive information from logs and responses.
4. Resource Limits
Resource limit problems occur when the APIs get too many requests from the users. Attackers exploit this to send fake requests to the servers. Certain APIs also allow consumers to request large payloads with a single call. This consumes system resources and also makes the service slow or even fail for the real users.
Organizations should establish user or IP-based request caps to manage resources. Implement considerable delay in requesting and blacklisting URLs that make an excessive amount of calls. Look out for attack-type request patterns with unusual characteristics.
5. Injection Attacks
APIs trusting user input without additional checks lead to injection attacks. From the client side, attackers send hidden special commands in standard-looking payloads like registration forms. Such commands/payloads can make databases leak sensitive information, execute system commands, or even change data that is stored. This happens when developers don’t implement input sanitizations and validation on user inputs.
Organizations should implement a validation check that will check all input data before it is used (to prevent injection attacks). Prevent malicious payloads by blocking special characters such as “<” and “>.” Use secure methods to communicate with the database. Place restrictions on input size and maintain lists for each API of what input types are permitted.
6. Improper Asset Management
APIs evolve rapidly as development teams continuously deploy new features and versions. This often leads to multiple API versions running simultaneously, with older versions remaining active for backward compatibility.
Development teams sometimes deploy test APIs to production environments, creating additional security risks. These forgotten, unused, or test APIs, often called “shadow APIs” or “zombie APIs,” typically contain outdated code and lack current security controls. Their known vulnerabilities and outdated security measures make them prime targets for attackers seeking the path of least resistance.
One way to better manage an organization’s APIs is to use API Inventory, which keeps a note of all versions of an API and where they run. Deprecate old versions of the API once newer ones start to function. If an API is for testing, leave it on a test server. Scan all API endpoints frequently for security issues. Use tools to identify hidden/shadow/Zombie APIs in your networks.
7. Mass Assignment
Mass assignment vulnerabilities occur when APIs automatically bind client-provided data to internal objects or database records without proper filtering. When an API accepts a data object for updates, it may blindly update all matching fields, including sensitive ones not intended for user modification. Attackers exploit this by adding these restricted fields to their requests, potentially escalating privileges or manipulating critical system values.
In order to prevent mass assignment, the organization should list which fields each API can update. Implement this to block the fields that are not on the list. Separate APIs for normal user and admin-level actions. Validate each field update with user permissions. Catch issues by testing APIs with additional fields in requests or implementing fuzzing tools.
8. Cross-Origin Resource Sharing
Cross-Origin Resource Sharing (CORS) rules regulate what websites can access an organization’s API. In simple terms, weak CORS configuration allows any site to call its API. During development, CORS is set to allow all origins. However, many times, organizations forget to change it later.
To overcome the problem of CORS, specific rules regarding which websites are allowed to consume the organization’s API must be implemented. Never set “allow-all” settings on live APIs. Verify CORS rules on how to put your APIs in force.
9. Lack of Endpoint Protection
Insufficient endpoint protection occurs when APIs have inconsistent security controls across their endpoints. While organizations might implement robust security checks on primary endpoints, deeply nested or less visible endpoints may lack the same level of protection. Attackers actively seek gaps in security coverage to bypass established security controls and gain unauthorized access.
Organizations must implement consistent security controls across all API endpoints, regardless of their visibility or network location. Apply the same security standards to every endpoint, including authentication, authorization, and input validation. Regularly scan all endpoints, including those in internal networks like staging and testing environments, to ensure uniform security coverage.
10. Improper Error Handling
If not properly handled, errors show attackers details of the database, the path of the server, or error dumps. Errors can also prevent the security checks from functioning. Attackers take advantage of the error message, gain insights into the API, and exploit it further.
Organizations should define standard error messages that conceal system details to improve error handling. Don’t send the exact same errors to both log files and users. If an error occurs, security checks should continue to work. For signs of attacks, organizations should regularly check error logs.
11. Security Misconfiguration
Security misconfiguration occurs if the settings in an API are set to a default setting, such as admin123, as the password. Most APIs begin with test passwords, open ports, or other fundamental security rules. To solve logical problems, organizations sometimes disable the security features and forget to re-enable them. Default settings, on the other hand, tend to make permissions more permissive than necessary as well as add non-essential functions that can make a system more problematic.
Organizations should set security configurations and change all default passwords and access rules. Disable unnecessary API functionalities that users do not need. Configure security rules for each part of the API according to its requirements. Regularly review API configurations to identify issues. Use security scanning tools that detect incorrect or missing security configurations.
12. Insecure Dependencies
Many third-party code packages are used when developing APIs to save time and resources. These packages are often well-known to have security issues. If APIs are using insecure packages under the hood, the attackers can exploit known issues to gain unauthorized access.
To secure dependencies, organizations should verify all packages for security issues prior to using them. Immediately install updates for packages when new security measures are released. Organizations should use open-source dependency scanning tools (SCA tools) that will alert them about insecure packages.
13. Lack of Proper Logging
Poor API logging generates security blind spots that can contain potential threats and undermine an organization’s ability to respond to them during an incident. Inadequate log management, e.g., saving logs in unreachable locations or not being able to protect the integrity of a log, can help attackers erase their traces or even reveal sensitive information.
To develop strong logging practices, organizations should log all API calls in detail, including information such as request headers and IP addresses, authentication methods used, response codes, etc. This involves using central, secure locations for the storage of logs and controlling who has access to each log.
14. Weak Encryption
Attackers are likely able to read or modify sensitive data if APIs use weak encryption. Certain organizations have APIs that use outdated encryption types that contain vulnerabilities. Others transmit trivial data in plain text. Even strong encryption can be weakened by a bad setup. Without a doubt, attackers choose weak points in API encryption to access sensitive data.
To secure APIs and the sensitive data they process, organizations should rely on strong encryption, such as AES. When transferring or saving private data, encrypt it. Use security guides to set encryption properly on the release of new security patches and update encryption.
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We use APIs in our everyday lives, not just for security, since we connect to digital worlds. API security threats and risks are rising as hackers seek new opportunities to exploit critical and hidden weaknesses. An API vulnerability can hijack systems, cause privilege escalations, or leave services vulnerable. Some businesses shut down due to API attacks, affecting user authentication, onboarding, and other processes. Tools like SentinelOne can mitigate API security risks and handle integrations seamlessly.
You can identify security issues well ahead of time before attackers do. It’s also important to note that implementing the best API security hygiene practices and not just relying on security tools to fix security flaws. By paying attention to these areas, you can save time, protect user data, and not jeopardize customer data. It will help you continue running business operations without severe disruptions or discontinuation.
FAQs
Three common API threats are broken access control, poor authentication, and injection attacks. Access control issues allow users to view sensitive data. Weakness in authentication allows attackers to bypass authentication mechanisms, and an injection attack sends malicious payloads to run arbitrary code, read/update/delete databases, and much more.
Broken authentication occurs when the authentication mechanism used by the API is misconfigured in some way or another. It includes the use of old login tokens (which should have expired), weak passwords, or relying on response bodies to log in users (response manipulation attacks). Such issues allow hackers to bypass authentication and access sensitive information.
Input validation is a well-known security best practice but is very often ignored while implementing APIs. Input validation analyzes all data sent by users to APIs to ensure that it is not malicious. In the absence of these checks, attackers can include malicious payloads hidden in normal-looking requests to perform injection attacks such as SQLi, XSS, etc.
Weak encryption in APIs makes it possible for attackers to intercept and decrypt sensitive data flowing between client and server. This allows them to steal passwords, payment details, and other confidential information.
Logging and monitoring help detect and respond to security threats by tracking unusual patterns, potential breaches, and suspicious activities in real-time. It provides an audit trail for investigating incidents and helps organizations understand how their APIs are being used or misused.
Security tools consist of tools such as API scanners, web firewalls as well as specialized platforms like SentinelOne above. Together, these tools help identify issues, filter unwanted traffic, and secure APIs against different security attacks.