42Crunch for Payment APIs

Payment APIs move sensitive financial data and must resist tampering, eavesdropping, and abuse. This scanner evaluates endpoints using read-only methods to surface configuration and implementation risks without sending destructive payloads. Findings map to PCI-DSS 4.0, SOC 2 Type II, and OWASP API Top 10 (2023) to help you prepare for audit evidence and control validation.

The scanner analyzes authentication schemes, authorization boundaries, and input handling common in payment flows. It detects JWT misconfigurations, including alg=none and weak key choices, and checks security headers and WWW-Authenticate compliance. BOLA and BFLA probes exercise ID and privilege endpoints to identify enumeration and role leakage. Property authorization checks assess over-exposure of internal fields and mass-assignment surfaces. Input validation highlights CORS wildcard usage with credentials and dangerous HTTP methods. Data exposure detection includes Luhn-validated card patterns, API key formats, and error leakage. Encryption checks cover HTTPS redirects, HSTS, and cookie flags. SSRF probes target URL-accepting parameters and internal IP detection. LLM security tests include adversarial prompts relevant to payment assistants and sensitive data extraction scenarios.

The scanner parses OpenAPI 3.0, 3.1, and Swagger 2.0 documents with recursive $ref resolution. It cross-references spec definitions against runtime behavior to find undefined security schemes, sensitive field exposure, deprecated operations, and missing pagination. This helps identify mismatches between declared and actual payment API behavior. For example, an operation marked as security: [] while requiring a bearer token in practice will be flagged as a potential authorization bypass.

Authenticated scans support Bearer, API key, Basic auth, and cookies. A domain verification gate using DNS TXT records or an HTTP well-known file ensures only the domain owner can submit credentials. The scanner only forwards a header allowlist including Authorization, X-API-Key, Cookie, and X-Custom-*. All checks remain read-only, with destructive payloads never sent. Private IPs, localhost, and cloud metadata endpoints are blocked at multiple layers. Customer data is deletable on demand and purged within 30 days of cancellation.

The Web Dashboard centralizes scan results, score trends, and branded compliance PDFs. The CLI supports commands such as middlebrick scan <url> with JSON or text output. The GitHub Action can gate CI/CD, failing builds when scores drop below a set threshold. The MCP Server enables scanning from AI coding assistants. Pro tier adds scheduled rescans, diff detection, email alerts, signed webhooks, and Slack or Teams notifications. Enterprise tiers provide unlimited APIs, custom rules, SSO, audit logs, SLA-backed support, and dedicated assistance.