OWASP Top 10

as an engineering risk map

The OWASP Top 10

is an awareness document for web application risk categories, not a certification checklist or a complete threat model. Each category maps to design, implementation, verification, monitoring, and response controls.

Security invariants

• TOP10-C1: OWASP Top 10
  is an awareness and risk-category document, not a complete application security standard or certification checklist.
• TOP10-C2: The 2025 categories begin with Broken Access Control, Security Misconfiguration, and Software Supply Chain Failures.
• TOP10-C3: Cryptographic Failures, Injection, and Insecure Design require distinct data, interpreter, and design controls.
• TOP10-C4: Authentication Failures are lifecycle failures across authenticators, recovery, sessions, throttling, and reauthentication rather than only weak passwords.
• TOP10-C5: Software or Data Integrity Failures require authenticated provenance, update, serialization, and replay boundaries.
• TOP10-C6: Logging and Alerting Failures concern actionable protected security telemetry, while Mishandling of Exceptional Conditions concerns safe behavior under errors and partial failure.

Trust-boundary map

Component	Responsibility
client	Legitimate Client
attacker	Adversarial Client or Supplier
edge	Web Edge and Request Boundary
application	Web Application
authorization	Object and Function Authorization
authentication	Authentication and Session Controls
configuration	Hardened Configuration Baseline
supply-chain	Dependency and Build Integrity Gate
crypto-service	Approved Cryptography and Key Policy
input-validator	Typed Input and Safe Interpreter Boundary
design-review	Threat Model and Abuse-Case Review
integrity-verifier	Software and Data Integrity Verifier
database	Protected Data Store
security-log	Security Logging and Alerting
error-handler	Bounded Exceptional-Condition Handler

Topology edges represent authenticated or otherwise explicit communication paths. Responses reuse those physical paths in reverse; no response-only or bypass edges are added.

Executable scenarios

a01-broken-access-control — A01 Broken Access Control

Authorization is enforced server-side for every object, function, tenant, and field instead of trusting routes, hidden UI, or caller-supplied identifiers.

▶Walkthrough: a01-broken-access-control (not found)

a02-security-misconfiguration — A02 Security Misconfiguration

Secure defaults, minimal services, repeatable configuration, safe headers, and drift detection replace one-time manual hardening.

▶Walkthrough: a02-security-misconfiguration (not found)

a03-supply-chain-failures — A03 Software Supply Chain Failures

Dependencies and artifacts are inventoried, pinned, verified against provenance and policy, and monitored throughout their lifecycle.

▶Walkthrough: a03-supply-chain-failures (not found)

a04-cryptographic-failures — A04 Cryptographic Failures

Data classification drives encryption and key management; approved authenticated encryption does not compensate for exposed keys or missing authorization.

▶Walkthrough: a04-cryptographic-failures (not found)

a05-injection — A05 Injection

Untrusted data remains data through parameterized APIs, typed parsers, contextual output handling, and explicit interpreter boundaries.

▶Walkthrough: a05-injection (not found)

a06-insecure-design — A06 Insecure Design

Threat modeling, abuse cases, security requirements, and architecture review address missing controls that scanning an implementation cannot invent.

▶Walkthrough: a06-insecure-design (not found)

a07-authentication-failures — A07 Authentication Failures

Phishing resistance, throttling, secure recovery, session rotation, and reauthentication protect the full authentication lifecycle.

▶Walkthrough: a07-authentication-failures (not found)

a08-integrity-failures — A08 Software or Data Integrity Failures

Code, updates, serialized data, and control messages are accepted only from authenticated sources under explicit integrity and replay policy.

▶Walkthrough: a08-integrity-failures (not found)

a09-logging-alerting-failures — A09 Security Logging and Alerting Failures

Security-relevant events carry stable context, are protected from tampering, reach actionable alerts, and never log secrets by default.

▶Walkthrough: a09-logging-alerting-failures (not found)

a10-exceptional-conditions — A10 Mishandling of Exceptional Conditions

Timeouts, partial failures, resource exhaustion, and unexpected state transitions are bounded, fail safely, and preserve invariants.

▶Walkthrough: a10-exceptional-conditions (not found)

Operational and failure rules

• Every rejection path fails closed at the component that owns the decision; infrastructure failure is never converted into authentication, authorization, or integrity success.
• Retries preserve stable transaction identity, replay detection, bounded freshness, and audit context. A retry does not erase a prior success or compromise signal.
• Concurrent validation branches are independent checks. Completion requires every mandatory branch, and no check substitutes for another.
• Logs contain decision metadata and stable identifiers, not credentials, bearer tokens, cryptographic keys, or sensitive payloads.

Related concepts

[CONCEPT]csrf-xss-protection [CONCEPT]api-security [CONCEPT]supply-chain-security [CONCEPT]threat-modeling-stride

Authoritative sources

1. OWASP Top 10
2. OWASP Top 10
   Introduction
3. OWASP Secure Product Design Cheat Sheet
4. OWASP Authentication Cheat Sheet