APIs are everywhere. They power your backend, mobile, and web apps, as well as microservices and third-party integrations, and they are under attack like never before.
A new survey by Traceable reveals that 57% of organizations have experienced an API-related data breach in the past two years, and 41% have endured five or more. (businesswire.com
) Traditional tools like WAFs and CDNs are failing at the API layer. (ciodive.com
If your APIs are not locked down, you are at risk.
These are 12 practices you need in your toolbox now. Each section tells you why it matters today and how to apply it right away.
- Use HTTPS with strong TLS configuration
Why it matters now
Unencrypted traffic is the low-hanging fruit for attackers. With more data moving between cloud, edge, and third-party APIs, a misconfigured TLS setup or expired certificate is enough for a serious breach.
How to do it
Enforce HTTPS for all endpoints. Disable HTTP.
Use TLS 1.2 minimum, ideally 1.3. Disable deprecated ciphers.
Enable HSTS with includeSubDomains so browsers refuse insecure connections.
Automate certificate renewal. Use trusted tools and test your setup regularly with services like Qualys SSL Labs.
- Secure delegated access using OAuth 2.0 correctly
Why it matters now
Many API breaches start with overprivileged tokens or misuse of OAuth flows. Teams under pressure often use insecure flows or fail to validate scopes and audiences.
How to do it
Use PKCE for public clients.
Avoid deprecated flows, such as implicit.
Issue short-lived access tokens and refresh tokens stored securely.
Validate scopes and audiences on resource servers.
Revoke tokens when suspicious activity is detected.
- Adopt WebAuthn for high assurance user authentication
Why it matters now
Passwords remain the weakest link. Phishing and credential theft are rising. WebAuthn provides a hardware or device-based credential model that is resistant to common attacks.
How to do it
Use WebAuthn for login or strong multi-factor authentication for sensitive APIs.
Ensure registration and attestation are handled properly.
Provide a secure fallback only where necessary, but avoid weak fallbacks such as email OTP.
- Leveled API keys with least privilege
Why it matters now
A single all-access key leak can give attackers full control. With the rise of third-party integrations and automation, key misuse becomes a bigger risk.
How to do it
Issue keys scoped by role, such as read, write, or admin.
Restrict keys by environment, IP, or referrer when possible.
Rotate keys frequently and automate rotation. Provide revocation when needed.
Store secrets securely, never in source control or public repositories.
- Enforce authorization at every boundary
Why it matters now
Broken object-level or function-level authorization remains one of the top API risks in OWASP’s API Top 10. (devguide.owasp.org
Attackers exploit missing checks on fields or permissions.
How to do it
Do authorization checks in backend logic for every action and object.
Never trust user-supplied identifiers.
Use attribute-based or relation-based models for complex domains.
Test authorization logic automatically and manually.
- Apply rate limiting and quotas to protect against abuse
Why it matters now
Bot attacks and fraud are increasing. Traceable’s report shows bot-driven attacks as one of the top challenges organizations face. (businesswire.com
)
How to do it
Apply per user, per key, and per endpoint rate limits.
Use algorithms like a token bucket or sliding window.
Send clear headers, such as quota remaining.
Return standard status codes such as 429 Too Many Requests.
- Version your API and manage deprecation clearly
Why it matters now
APIs evolve. Without versioning and clear deprecation, clients break. Teams often patch around issues, which creates security gaps.
How to do it
Define a version strategy, such as URI path or headers.
Announce deprecation schedules early.
Monitor usage of versions.
Use feature flags to manage changes.
- Use allow lists and network restrictions
Why it matters now
Shadow APIs and internal endpoints are frequent breach vectors. Restricting access with network controls reduces exposure.
How to do it
Apply IP allow lists, VPC endpoints, or mutual TLS for internal or partner endpoints.
Keep allow lists up to date and audit changes.
Always combine network restrictions with authentication and authorization.
- Align with the OWASP API Security Top 10
Why it matters now
The OWASP API Security Top 10 highlights current real-world risks such as Broken Object Level Authorization, Broken Authentication, and Excessive Data Exposure. (devguide.owasp.org
)
How to do it
Use the Top 10 as a framework in design, code review, and testing.
Map each endpoint to threats.
Prioritize fixes that are easiest to exploit or most exposed.
- Use an API gateway as central control
Why it matters now
Gateways enforce policies such as authentication, authorization, TLS, and rate limits at scale. But many teams do not configure or monitor them correctly. Only 19% of organizations rate their API defenses as highly effective. (ciodive.com
)
How to do it
Put a gateway in front of APIs and use it for cross-cutting concerns.
Integrate with your identity provider, logging infrastructure, and WAF rules.
Do not push all logic into the gateway. Services must still validate critical checks.
- Validate input and handle errors securely
Why it matters now
Mass assignment, improper validation, and verbose error messages continue to be exploited. A recent study found many REST APIs still vulnerable to mass assignment. (arxiv.org
)
How to do it
Validate input schemas strictly and reject unexpected fields.
Sanitize and canonicalize inputs.
Do not send stack traces or internal errors to clients. Log them internally.
Define error responses that are consistent and minimal.
- Log, monitor, and build an incident response plan
Why it matters now
Even with best practices, breaches happen. In Traceable’s survey, 73% of those breached experienced multiple incidents. (ciodive.com
)
How to do it
Log authentication failures, suspicious payloads, and data exports.
Centralize logs and set up alerts for anomalies.
Create and rehearse a runbook for API incidents that covers key revocation, token invalidation, and communication.
Final Thoughts
API security in 2025 is not about writing a single perfect system. It is about building layers of defense.
HTTPS, OAuth, WebAuthn, leveled keys, authorization, rate limiting, versioning, allow lists, validation, gateways, and logging all work together to reduce risk.
Start with what your system lacks most. If you are missing proper authorization checks or using overly privileged keys, fix those first. If traffic is unmonitored, build visibility. Use recent breach reports and the OWASP Top 10 to guide what to secure next.
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