Learn about the 10 most critical API security risks and scan your API for free.
Scan API for OWASP RisksThe OWASP API Top 10 is the authoritative list of the ten most critical API security risks, compiled by the Open Worldwide Application Security Project (OWASP). The latest 2023 edition reflects the evolving threat landscape in the API-first era.
APIs have become the primary attack surface for modern web applications, accounting for over 80% of all web traffic. Understanding these 10 risks is the minimum requirement for any organization building or consuming APIs.
SEC Scanner automatically tests your API against all 10 OWASP API Top 10 risk categories, plus many additional vulnerability types.
BOLA is the #1 API security risk. APIs expose object identifiers (like user IDs or order numbers) in requests, and when the server doesn't verify that the requesting user has permission to access that specific object, attackers can simply change an ID to access other users' data.
Unauthorized access to any user's data, including personal information, financial records, and private content.
Implement object-level authorization checks on every endpoint. Never rely solely on the object ID — always verify the requesting user's ownership or access rights.
Authentication mechanisms in APIs are often implemented incorrectly, allowing attackers to compromise authentication tokens or exploit implementation flaws to assume other users' identities.
Complete account takeover, identity theft, unauthorized access to all user data and functionality.
Use standard authentication protocols (OAuth2, OpenID Connect). Implement proper session management, rate limiting on login endpoints, and multi-factor authentication.
This category combines excessive data exposure and mass assignment. APIs may return more fields than necessary or accept write operations on fields the user shouldn't modify.
Exposure of sensitive data fields (internal IDs, hashes, PII) or unauthorized modification of critical fields (role, isAdmin, permissions).
Implement field-level authorization for both read and write operations. Use DTOs to control exactly which fields are returned and which can be modified.
APIs without rate limiting, payload size restrictions, or execution timeouts can be abused to exhaust server resources, leading to denial of service or inflated cloud bills.
Service downtime, increased infrastructure costs, degraded performance for legitimate users.
Implement rate limiting, pagination, payload size limits, and execution timeouts. Monitor resource consumption patterns.
When administrative functions aren't properly protected, regular users can access admin-only endpoints by simply knowing the URL. This often happens when APIs rely on UI hiding rather than server-side authorization.
Full administrative access, ability to modify other users, change system settings, or delete data.
Implement function-level authorization checks on the server side. Never rely on UI hiding as a security measure. Use role-based access control.
Some API endpoints expose business-critical operations without adequate protection against automation, allowing attackers to script these flows at scale.
Fake account creation, data scraping, inventory manipulation, financial fraud.
Implement anti-automation measures: CAPTCHAs, step-up authentication, transaction limits, and device fingerprinting.
SSRF occurs when an API fetches a remote resource without validating the user-supplied URL. Attackers can make the server send requests to internal services or cloud metadata endpoints.
Access to internal services, cloud credential theft (AWS/GCP metadata), network reconnaissance.
Validate and sanitize all URLs. Use allowlists for permitted domains. Block requests to internal IP ranges and cloud metadata endpoints.
Misconfigured APIs expose verbose error messages, debug endpoints, default credentials, or missing security headers. These often arise from default configurations not hardened for production.
Information disclosure, unauthorized access through default credentials, Cross-Origin attacks.
Harden API configurations before deployment. Remove debug endpoints, implement proper CORS policies, add security headers, change default credentials.
Organizations often run outdated API versions, undocumented endpoints, or exposed admin panels. These forgotten APIs are rarely patched and lack security controls.
Attackers exploit unpatched vulnerabilities in old API versions or discover hidden administrative functionality.
Maintain an API inventory. Document all endpoints and versions. Decommission old versions. Monitor for unauthorized API deployments.
Your API's security depends on the security of third-party APIs it consumes. If your API blindly trusts data from external services, a compromised service can inject malicious data into your system.
Data poisoning, injection attacks through trusted third-party data, supply chain compromises.
Validate and sanitize all data from third-party APIs. Don't trust external data more than user input. Monitor third-party API behavior.
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