Failure to enforce restrictions on what authenticated users can do; most prevalent web application risk

OWASP Top 10

Details
Full Name

OWASP Top 10 Web Application Security Risks

Also known as

OWASP Top Ten, Web Application Security Top 10

Core Concepts:

A01 – Broken Access Control

Failure to enforce restrictions on what authenticated users can do; most prevalent web application risk

A02 – Cryptographic Failures

Sensitive data exposed due to weak or absent encryption; previously called "Sensitive Data Exposure"

A03 – Injection

Untrusted data sent to an interpreter as part of a command or query (SQL, OS, LDAP injection)

A04 – Insecure Design

Missing or ineffective security controls resulting from flawed design and threat modeling

A05 – Security Misconfiguration

Insecure default settings, incomplete configurations, open cloud storage, verbose error messages

A06 – Vulnerable and Outdated Components

Use of components (libraries, frameworks) with known vulnerabilities

A07 – Identification and Authentication Failures

Weaknesses in authentication, session management, and credential handling

A08 – Software and Data Integrity Failures

Code and infrastructure that does not protect against integrity violations (e.g., insecure deserialization, CI/CD tampering)

A09 – Security Logging and Monitoring Failures

Insufficient logging, detection, and response to breaches

A10 – Server-Side Request Forgery (SSRF)

Server fetches remote resources from attacker-controlled URLs without validation

Key Proponent

OWASP Foundation (https://owasp.org/Top10/, first published 2003; the list above is the 2021 edition)

When to Use:

  • Performing security risk assessments on web applications

  • Establishing secure coding guidelines and developer training programs

  • Conducting threat modeling and security design reviews

  • Prioritizing security findings during code reviews and penetration tests

  • Defining acceptance criteria for security requirements

  • Auditing third-party or open-source components for known vulnerabilities

Current Status:

  • The list above is the 2021 edition. The current released edition is OWASP Top 10:2025 (RC November 2025, finalized around the turn of 2025/26): it adds Software Supply Chain Failures (A03) and Mishandling of Exceptional Conditions (A10), folds SSRF into Broken Access Control, and re-ranks several categories (what changed)

  • An LLM’s training-data prior for "OWASP Top 10" most plausibly serves the 2021 edition — it was current for over four years and dominates tutorials, courses, and blog material; models with earlier cutoffs may even blend in 2017

  • Name the edition explicitly in prompts ("OWASP Top 10:2025" vs ":2021") — bare category IDs are ambiguous across editions: A03 means Injection in 2021 but Software Supply Chain Failures in 2025