Key insights: Secure APIs and Interfaces
Secure APIs and integrations: OWASP API risks, validation, auth patterns and testing that keep interfaces from becoming the weak link.
Why API security goes beyond classic web security
APIs are the backbone of modern integrations and apps – and a prime target. Unlike a website, an API exposes many endpoints, granular object access and automated clients. That creates risks a UI-focused defence misses, above all Broken Object Level Authorization (BOLA), where access is not checked per object. We address API security as part of interface development and IT security.
OWASP API Security Top 10
We align design and testing with the OWASP API Security Top 10: broken object- and function-level authorisation, excessive data exposure, lack of rate limiting, security misconfiguration and more. They provide a proven baseline for secure interfaces – complemented by Security by Design.
Authentication and authorisation (OAuth2, JWT, mTLS)
We use OAuth2 and short-lived JWTs for user-related access and API keys with rotation for server-to-server calls; mTLS for high requirements. Authorisation is enforced per object and function, not just at the gateway.
Rate limiting, input validation and schema checks
Rate limiting and quotas slow brute force and scraping; strict input validation and schema checks against the OpenAPI specification prevent injection and malformed requests. Sensitive data never ends up in logs.
API penetration testing and monitoring
We verify interfaces with targeted API penetration testing and continuous monitoring of anomalies – consistent with the technical GDPR measures for personal data.
Frequently asked questions about Secure APIs and Interfaces
- Why isn't classic web security enough for APIs?
- APIs often have many endpoints, automated clients and granular object access. Typical flaws like Broken Object Level Authorization (BOLA) arise when each object access does not verify whether the calling user is authorised – pure UI hardening does not cover this.
- What are the OWASP API Security Top 10?
- A list of the most common API vulnerabilities, including broken object- and function-level authorisation, excessive data exposure, missing rate limiting and security misconfiguration. We align design and testing with this list.
- OAuth2/JWT or API keys – which is more secure?
- API keys suit server-to-server calls with rotation. For user-related access, OAuth2 and short-lived JWTs are usually better because they control permissions and validity fine-grained. Often both are combined depending on the use case.
- How does rate limiting prevent abuse?
- Rate limiting caps calls per client and time. It slows brute force, scraping and denial-of-service and protects backend resources. It is best complemented by quotas, throttling and monitoring of suspicious patterns.
- How can API security be tested?
- Via automated scans (e.g. missing headers, known vulnerabilities), schema validation against the OpenAPI specification and targeted API penetration testing that checks authorisation, input validation and business logic.
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