learn/phase-3/p3-w11/lesson 1.5
Milestone 11 · lesson 1.5

OWASP Top 10 2025: What Changed and Why It Matters

Overview of the 2025 update and how it maps to threats you'll encounter in this course.
Capture-the-Flag Labsoon

A hands-on flag hunt for this lesson, coming soon.

What you'll learn

  • Understand the OWASP Top 10 2025 release and what vulnerabilities are now priorities.
  • Know the top 3 threats in 2025 and why they've evolved.
  • Recognise new threats like SSRF (Server-Side Request Forgery) and Insecure Design.
  • Map this course's lessons to the official 2025 list.

OWASP Top 10 2025: What Changed and Why It Matters

The OWASP Top 10 is a community-maintained shortlist of the 10 most critical web application security risks. It gets updated every 3-4 years as threats evolve. The 2025 release reflects the reality of modern applications: cloud infrastructure, supply-chain dependencies, and emerging attack vectors.

The Top 10 in 2025

RankVulnerabilityWhat It Is2021 vs 2025
1Broken Access ControlUsers access resources they shouldn't. IDOR is the classic example.Moved up from #5
2Cryptographic FailuresEncryption is weak, missing, or broken. Previously "Sensitive Data Exposure".Renamed
3InjectionSQL, OS commands, LDAP—untrusted input reaches code interpreters.Stable
4Insecure DesignSecurity was never part of the design; the architecture is fundamentally flawed.NEW
5Security MisconfigurationDefault credentials, unnecessary services, outdated frameworks exposed.Stable
6Vulnerable and Outdated ComponentsUsing libraries with known exploits.Stable
7Authentication FailuresWeak passwords, credential stuffing, broken session management.Stable
8Software and Data Integrity FailuresCompromised dependencies, malicious updates, unsigned deployments.NEW
9Logging and Monitoring FailuresNo alerts on attacks; no trail for investigation.Stable
10Server-Side Request Forgery (SSRF)App is tricked into making requests to internal services.NEW

Three New Entries in 2025

Insecure Design (Rank #4)

Why it entered: OWASP split design-level flaws from implementation bugs.

What it means: A perfectly coded app with bad architecture is still insecure. You can't patch your way out of it—you have to redesign.

Example: An app that sends all data unencrypted because encryption was never considered in the design.

Software and Data Integrity Failures (Rank #8)

Why it entered: Supply-chain attacks have become mainstream.

What it means: You depend on third-party libraries. If one is compromised, your entire app is compromised.

Example: Malicious code injected into a popular npm package. Every app using it is now infected.

Server-Side Request Forgery / SSRF (Rank #10)

Why it entered: Cloud adoption created a new attack surface.

What it means: Modern apps have internal services and cloud metadata endpoints that should never be reachable from the internet. SSRF tricks the app into accessing them.

Example: An app downloads images from user-provided URLs. An attacker sends http://169.254.169.254/ (AWS metadata endpoint), and the app fetches AWS credentials.

What Changed from 2021?

  • Up: Broken Access Control moved from #5 to #1—it's now the #1 risk.
  • Renamed: Sensitive Data Exposure → Cryptographic Failures (more precise).
  • New: Three categories entered: Insecure Design, Software/Data Integrity Failures, SSRF.
  • Dropped: Cross-Site Scripting (XSS) and Deserialization fell out of top 10 (still serious, but lower priority statistically).

How This Course Maps to OWASP 2025

OWASP 2025 RiskWhere It's Taught
Broken Access ControlIDOR lesson ✓
Cryptographic FailuresTLS lesson (Phase 1) ✓
InjectionSQL Injection + Command Injection ✓
Insecure DesignArchitecture lessons (framework-dependent)
Security MisconfigurationLinux hardening (Phase 2) ✓
Vulnerable & Outdated ComponentsLab context ✓
Authentication FailuresSession management ✓
Software & Data IntegrityCSRF lesson ✓
Logging & MonitoringWeb server logs (lab context)
SSRFComing soon

The Real Takeaway

The 2025 list reflects a shift in how the world builds apps:

  1. Cloud is standard. Internal services are now attack targets (SSRF).
  2. Supply chain is the perimeter. Dependencies are your responsibility (Integrity Failures).
  3. Design matters more than code. Bad architecture can't be fixed with patches.
  4. Encryption is non-negotiable. It moved up the priority list.

Use the OWASP Top 10 2025 as your testing checklist. Work through the list in order, and you'll find the majority of real vulnerabilities in any app.

Check your understanding

3 questions

Type an answer and press Check. Grading is keyword-based and forgiving, so short answers are fine.

  1. 1

    What two new threats entered the top 10 in 2025 that weren't in 2021?

  2. 2

    Which 2021 risk disappeared from the top 10 in 2025?

  3. 3

    What's the difference between Insecure Design and Security Misconfiguration?