If you fail to lock it, the breach is inevitable.
A Rest API security review is not a checklist; it is an investigation. Attackers probe for weak authentication, exposed data, misconfigured permissions, and flawed error handling. Each gap is a possible exploit. The goal is to identify and eliminate those gaps before they are found in the wild.
Start with authentication. Use strong token-based methods like OAuth 2.0 or OpenID Connect. Reject weak or reusable tokens. Force expiration and rotation. Confirm that access tokens are scoped tightly to what the client needs, nothing more. Check every endpoint. If even one route skips authentication, your whole system is compromised.
Move to authorization. Validate that role-based access control, policy enforcement, and data-level permissions are applied consistently. A missing permission check on a single query can expose entire datasets. Automated permission tests catch blind spots faster than manual inspection.
Encrypt transport. Use HTTPS with TLS 1.2 or above for all requests. Block plaintext traffic. Redirect insecure requests to secure equivalents. Inspect certificates and cipher suites regularly.
Sanitize input. Treat every parameter, header, and payload as hostile. Apply strict schemas. Reject unexpected or malformed data. Encode all output to neutralize injection attacks. Logging input is not enough; review logs for anomalies and potential breaches.