API marketplaces security

API marketplaces expose a large surface through public catalog endpoints, runtime configuration APIs, and callback registration paths. The primary risks stem from weak authentication on marketplace management planes, over-permissive scopes, and insecure webhook delivery. Black-box scanning can validate authentication controls, inspect security headers, and probe for IDOR across catalog and subscription APIs. Because marketplaces often aggregate third-party APIs, the attack surface includes supply chain risks such as exposed API keys and callback URL manipulation.

Marketplace APIs commonly use bearer tokens, API keys, and OAuth flows; misconfigurations in these schemes are high-impact findings. Issues such as JWT alg=none, weak key derivation, missing nonce validation, and insufficient scope scoping can allow lateral movement across tenant boundaries. The scanner checks for JWT misconfigurations, validates security header presence, and tests authorization logic by probing for BOLA and BFLA patterns without destructive payloads.

• JWT token validation and algorithm confusion checks.
• Security header and WWW-Authenticate compliance.
• Over-privileged scopes and tenant isolation failures.
• Admin endpoint exposure and privilege escalation paths.

Catalog endpoints that list APIs, plans, and pricing must guard against mass-assignment and over-exposure of internal fields. Subscription management surfaces often reveal sequential identifiers, enabling IDOR through adjacent ID probing. Property authorization flaws can expose sensitive configuration fields such as internal quotas or billing metadata. The scanner maps these findings to OWASP API Top 10 and supports audit evidence for SOC 2 Type II and PCI-DSS 4.0 by validating access control boundaries.

Webhook registration is a common marketplace feature; insecure callbacks can be redirected to attacker endpoints, leading to event replay or data injection. URL-accepting parameters in configuration APIs may introduce SSRF risks, and missing validation on third-party endpoints increases supply chain exposure. The scanner detects open redirect patterns, validates callback URL formats, and identifies dangerous HTTP methods while explicitly excluding intrusive injection tests that are out of scope.

Marketplaces that integrate LLM-based components expose prompts and model configurations through management APIs. The scanner includes multiple AI security probe tiers that test for system prompt extraction, instruction override attempts, DAN and roleplay jailbreaks, data exfiltration techniques, token smuggling, and prompt injection vectors. These tests are non-intrusive and designed to surface configuration weaknesses without affecting downstream services.