APIs authenticate using tokens, keys, and secrets that developers handle carelessly. These credentials appear in public GitHub repositories, get hardcoded into mobile applications, and leak through various channels whilst providing unrestricted access to backend systems. Organisations implement robust authentication for user-facing applications whilst API credentials receive minimal protection. This creates situations where stealing API keys proves easier than compromising user accounts whilst granting similar or greater access.
Common API Authentication Mistakes
API keys embedded in client-side code become public the moment applications deploy. Mobile apps and JavaScript code contain API credentials that anyone can extract. Developers treat these credentials as configuration rather than secrets requiring protection. Long-lived API tokens enable attackers who compromise them to maintain persistent access. Unlike user passwords that change regularly, API tokens often remain valid indefinitely unless explicitly revoked. This permanence makes compromised API credentials particularly valuable to attackers.
Expert Commentary
Name: William Fieldhouse
Title: Director of Aardwolf Security Ltd
Comments: “API authentication assessments consistently find credentials in places they shouldn’t be: public repositories, mobile app binaries, and even in API responses themselves. Organisations implement proper authentication for users whilst leaving APIs accessible with static keys that never expire or rotate.”
Securing API Authentication
Implement proper OAuth flows rather than static API keys for user-specific operations. OAuth tokens scope access appropriately, expire automatically, and enable revocation when compromised. This approach provides security benefits that static keys can’t deliver. Rotate API credentials regularly and implement automatic expiration. Like passwords, API keys should change periodically. Automated rotation reduces impact of credential leaks by limiting how long compromised credentials remain valid.
Regular web application penetration testing must include API authentication testing. Professional assessment identifies where API credentials leak or can be compromised, revealing authentication weaknesses before attackers exploit them.
Store API secrets securely using proper secrets management solutions. Credentials shouldn’t live in source code, configuration files, or environment variables. Dedicated secrets management provides encryption, access control, and audit logging that file-based storage lacks.
Working with the best penetration testing company experienced in API security provides validation that API authentication actually protects against real attack scenarios.
API authentication requires same attention given to user authentication. The access API credentials provide demands proportional protection rather than treating API keys as configuration details requiring minimal security.
