APIsec for OAuth providers

middleBrick scans OAuth provider implementations for common configuration and integration weaknesses. The engine treats your authorization endpoint, token endpoint, and userinfo endpoint as runtime targets while mapping findings to OWASP API Top 10 (2023) and PCI-DSS 4.0 alignment language.

Black-box scanning verifies redirect URI validation, state parameter handling, scope enforcement, and token introspection behaviors without requiring code or SDK access. Because the scan is read-only, it checks for insecure redirects, missing Proof Key for Code Exchange (PKCE) indicators, and open configuration endpoints that could weaken provider integrity.

OpenAPI specifications are parsed when available to compare declared OAuth flows against observed runtime behavior. This helps you prepare for audit evidence around authorization server hardening and supports controls relevant to SOC 2 Type II review of identity access management.

The scanner evaluates authentication bypass risks specific to OAuth providers, including malformed bearer tokens, weak signature validation, and JWT misconfigurations such as alg=none or missing nonce values. It inspects WWW-Authenticate headers for compliance expectations and authorization server error handling that may leak stack traces.

Authenticated scanning allows the tool to exercise protected endpoints using Bearer tokens, API keys, Basic auth, and cookies. Before credentials are accepted, a domain verification gate confirms ownership via DNS TXT record or an HTTP well-known file, ensuring that only the domain owner can run credentialed checks.

Header forwarding is limited to Authorization, X-API-Key, Cookie, and X-Custom-* headers, reducing noise and preserving provider integrity during security assessment.

middleBrick probes for OAuth-specific misconfigurations including overly permissive CORS rules on token endpoints, dangerous HTTP methods left exposed, and debug endpoints that should not be present in production authorization flows.

• Redirect URI manipulation tests to confirm strict whitelist enforcement.
• Scope escalation attempts to identify missing server-side validation.
• Token introspection endpoint exposure and unintended metadata leakage.
• Sensitive data in authorization code fragments or implicit flow responses.
• Server fingerprinting risks from provider version headers or error messages.

Findings are cross-referenced against OpenAPI definitions to highlight undefined security schemes or deprecated operations that weaken provider resilience.

Pro tier continuous monitoring runs scheduled rescans at intervals of six hours, daily, weekly, or monthly, and detects diffs between scans such as new findings, resolved issues, and score drift. Email alerts are rate-limited to one per hour per API to avoid notification fatigue.

When findings change, HMAC-SHA256 signed webhooks are emitted with auto-disable after five consecutive failures, enabling integration with deployment pipelines or incident response systems without introducing fragile dependencies.

For OAuth providers, this supports ongoing alignment with security controls described in regulatory frameworks and provides timely evidence when configurations evolve over time.

middleBrick does not fix, patch, block, or remediate OAuth configuration issues; it detects and reports with remediation guidance. It does not perform active SQL injection or command injection tests, which fall outside its non-intrusive scope.

Business logic vulnerabilities related to consent screens, custom grant types, or proprietary authorization workflows require domain expertise that automated scanning cannot replace. Blind SSRF checks are also out of scope because out-of-band verification is not feasible in this context.

The tool does not replace a human pentester for high-stakes audits and should be used as part of a broader security program that includes manual review and architectural threat modeling.