An IT ecosystem consists of various applications that need to communicate with one another to work effectively. For example, an organization’s customer relationship management (CRM) solution may need to share information with its financial department’s invoicing application. Application Programming Interfaces (APIs) enable these kinds of applications to communicate, often transmitting sensitive data from one location to another. Knowing that APIs create additional attack vectors that are often difficult for organizations to secure, malicious actors increasingly use API vulnerabilities as part of their attacks.
To mitigate API security vulnerability risk, organizations need to have strategies for identifying and testing APIs.
What are API Security vulnerabilities?
API vulnerabilities are potential design, implementation, or usage weaknesses that malicious actors can exploit to compromise systems and data. They pose security, compliance, and operational risks because attackers can use them to:
- Gain unauthorized access to systems, networks, applications, and data
- View, modify, or delete data, undermining its confidentiality, integrity, and availability
- Disrupt services, causing business interruption
Common issues that lead to API vulnerabilities include:
- Lack of authentication and authorization mechanisms: allowing unauthorized users to access sensitive data or perform unauthorized actions
- Insufficient user input validation and output encoding: exposing APIs to injection attacks that enable malicious actors to insert malicious code
- Inadequate access control: accidentally exporting sensitive data or functionalities to unauthorized users
- Poor error handling and logging: revealing details in error messages or failing to log security-relevant activities
Why are APIs so vulnerable?
While APIs are not inherently vulnerable, several factors make them riskier than other technologies:
- Proliferation: As organizations incorporate more Software-as-a-Service (SaaS) applications, they add more APIs to connect them, expanding their attack surface further.
- Lack of visibility: Organizations often have no way to identify all APIs, creating security blind spots that attackers can exploit.
- Speed of deployment: Developers must implement APIs quickly, creating human error risks as secure coding technologies, like Static Application Security Testing (SAST) and Dynamic Application Security Testing (DAST) tools, were not designed for APIs.
- Exposure: Public APIs connect applications across the public internet, possibly sharing private endpoint information that attackers can exploit.
What are common examples of API attacks?
Mitigating security risks often means “thinking like an attacker.” As you work toward protecting your APIs, you should consider the following common types of API attacks:
- Brute force: using automation to try combinations of login credentials and access tokens, hoping that one grants unauthorized access
- Denial of Service (DoS): sending high volumes of requests to the API, hoping that it becomes unresponsive and making it unavailable to legitimate users
- Injection: inserting malicious code into API inputs, hoping to manipulate functions or data through unauthorized access
- Man in the Middle (MitM): intercepting and changing communications between the API client and server, hoping to gain unauthorized access to data
OWASP Top 10 API Security risks.
The Open Worldwide Application Security Project (OWASP) is a non-profit, community-led organization whose projects support its mission of securing software. In 2023, OWASP published an updated version of its API Security Top Ten that outlines the following ten threats that their community believes pose the greatest risk to API security:
- Broken Object Level Authorization: API fails to properly enforce access controls at the code level so unauthorized users can manipulate an object ID, like sequential integers or generic strings.
- Broken Authentication: API lacks proper authentication mechanisms, which places endpoints and flows at risk.
- Broken Object Property level Authorization: API fails to validate that a user should have access to the specific object property when accessing an object using an API endpoint.
- Unrestricted Resource Consumption: API fails to place or inappropriately sets limits on the number of requests that require resource use, like bandwidth, CPU, memory, or storage.
- Broken Function Level Authorization: The API’s authorization mechanism fails to manage complex hierarchies, like checking user access across different roles or groups.
- Unrestricted Access to Sensitive Business Flows: API exposes resources and workflows that support the business requirements.
- Server Side Forgery Request: API fails to properly validate user-supplied URL when fetching a remote resource.
- Security Misconfiguration: API contains unpatched vulnerabilities, common endpoints, services with insecure default configurations, or unprotected files and directories.
- Improper Inventory Management: API documentation fails to inventory assets or retirement strategies, leading to documentation and data flow blindspots.
- Unsafe Consumption of APIs: External API relies on weaker security requirements provided by the third-party provider.
Best practices for securing APIs.
Your company’s digital strategy is critical to its business operations and revenue objectives. To take a step toward securing the APIs that enable these goals, you can follow some best practices.
Identify all APIs.
You can’t secure an API that you don’t know exists within your ecosystem. Before implementing any other security controls, you should identify all public-facing and internal APIs, including managed and unmanaged ones. To gain visibility into your API footprint, you should look for a runtime API security solution that identifies and analyzes:
- Published, shadow, and deprecated APIs
- Traffic patterns to understand usage
- API specifications
- Headers, parameters, and response codes
- Access to regulated data
Implement a Web Application Firewall (WAF).
A WAF can filter and block malicious API requests, mitigating DoS attack risks. When choosing a WAF, you should look for one that:
- Protects against OWASP Top 10 API security risks
- Profiles traffic
- Efficiently allows or blocks access
- Enables customization to create environment-specific rules
Generate security test cases.
To identify API security vulnerabilities, you should engage in runtime testing that can help you implement security best practices like:
- Strong, role-based access controls (RBAC)
- Strong authentication, like using OAuth2 or API keys to identify the API consumer
- Regularly applying updates and security patches to remediate critical vulnerabilities
Monitor for changes.
As your organization integrates new services or updates current APIs, you may experience configuration changes that negatively impact security. To mitigate these risks, you should:
- Continuously monitor for changes
- Categorize findings by risk level and hosting provider
- Review trends over time to continuously improve security
Implement API security controls with UltraAPI.
Vercara UltraAPI, powered by Cequence, empowers your organization to stop API attacks with a single integrated solution. UltraAPI addresses all phases of your API protection lifecycle, from discovery to runtime in production. With our broad library of network integrations, you can analyze and protect your APIs using passive, inline, or API-based integrations with your existing network components. Additionally, we provide a large API security threat database containing billions of records that enable you to compare real-world exploits against your organization’s API vulnerabilities for enhanced risk rating and remediation prioritization.
To learn more about how UltraAPI can help your organization stop API attacks, visit the product page.
