I‘m thrilled to see your interest in strengthening your ethical hacking abilities! As an experienced cybersecurity analyst, I can definitively say that hands-on practice is critical for gaining technical prowess and a hacker mindset. The good news is there are now many fantastic intentionally vulnerable web applications available for developing your skills safely and legally.
In this comprehensive guide, I’ll share my top recommendations for using "vulnerable by design" web apps to take your penetration testing game to the next level. You’ll discover applications ideally suited for your experience level, detailed technical explanations of flaws, tips for configuration and troubleshooting, and guidance for staying responsible.
Let‘s start with an overview so you know how purposefully insecure web apps can unlock your ethical hacking potential.
Why Learning with Vulnerable Web Apps is So Valuable
Intentionally vulnerable web apps provide the perfect legal sandbox for you to test hacking techniques safely. They are designed specifically for security practitioners to discover and exploit weaknesses in application code without entering legal or ethical gray areas.
Here are five key reasons hands-on practice against vulnerable by design targets is so beneficial:
1. Train Against Realistic Flaws in Low-Risk Environment
Purposefully designed apps contain many of the actual vulnerabilities found in production applications and services today:
- Injection attacks like SQLi and OS command injection
- Broken authentication and session management
- Cross-site scripting (XSS)
- Insecure data exposure
- Broken access controls
And the list goes on. Without affecting any real sites, you can thoroughly test techniques to identify and exploit each weakness class following ethical disclosure principles. There‘s no worry of getting in trouble legally when using these designated cyber training grounds!
2. Flex Your Hacking Skills Hands-On
Reading about application flaws only gets you so far. By manually probing insecure apps‘ defenses, you gain practical intuition and hacking instincts. Repeated testing builds vital skills in:
- Mapping attack surfaces
- Analyzing security configurations
- Understanding how flaws actually work
- Targeting weaknesses with specialized tools
- Customizing payloads to bypass protections
These lessons prepare you to battle test production systems and uncover novel bugs.
3. Measure Expertise Gains Over Time
Ever feel lost trying to gauge your progress in hacking independently? Public vulnerable apps provide built-in benchmarks to measure practical knowledge gains.
Completing increasingly advanced vulnerability exercises demonstrates concrete growth. Trouble-free exploitation today might have seemed impossible just months ago.
Rubbing up against real code problems accelerates competency faster than any tutorials or certifications alone.
4. Discover Your Weaknesses Through Regular Practice
Ever feel like you have gaps holding back your hacking skills? Purposefully vulnerable apps help uncover where your technical or mindset deficiencies lie through continuous experimentation.
Difficulty bypassing certain protection mechanisms reveals areas needing work. Frequent practice shining light in your blindspots is the only way to strengthen those weaknesses.
5. It‘s 100% Legal Ethical Hacking Training
This last reason is the whole foundation on which vulnerable web app training stands. Using intentionally insecure programs as ethical hackers follows all legal and ethical guidelines around authorized security research.
The applications welcome good-faith vulnerability probing and disclosure as part of the intended use case. As long as you respect the rules of engagement for these cyber practice ranges, testing and reporting remains above board.
I don‘t know about you, but I’m ready to start exploring some prime intentionally vulnerable apps after seeing those benefits!
Overview of Featured Web Application Security Practice Tools
There are extremely popular vulnerable by design applications spanning all skill levels and technologies:
WebGoat – OWASP’s long-running web app “Swiss army knife” for learning application security concepts
JUGS – Realistic vulnerable online banking application modeled after popular financial sites
Damn Vulnerable Web App (DVWA) – Highly accessible PHP/MySQL app intentionally developed with major flaws
Mutillidae – Huge collection of 50+ OWASP Top 10 vulnerabilities in a PHP testbed
NodeGoat – OWASP Node.js web app for finding JavaScript and Node.js specific weaknesses
Web Security Dojo – Ubuntu virtual machine preloaded with multiple vulnerable test apps
And more…
Now let’s explore some leading options in more detail.
OWASP WebGoat: The Gold Standard for Guided Lessons
One of the first intentionally vulnerable apps, WebGoat remains popular for beginners through experts. Available via GitHub, WebGoat is a Java web app maintained by OWASP as an application security teaching tool.
Each WebGoat lesson highlights a specific type of common weakness like injection attacks or access control issues. You “pass” lessons by successfully exploiting the example flaw in WebGoat’s code. This hands-on learning style helps developers and testers deeply understand vulnerabilities from an attacker’s point of view.
With beginner through advanced practical exercises, WebGoat scaffolds learning for practitioners at all levels. Detailed explanations walk through how vulnerabilities work while code examples demonstrate secure implementation best practices.
Additional WebGoat content like WebGoat Legacy and WebGoat.NET provide cross-language training on flaws beyond Java systems.
Key WebGoat Features:
✅ Step-by-step vulnerability lessons covering 8 major web risk types
✅ SQL Injection, XSS, and Insecure Deserialization labs
✅ Reference solutions to check exploit code against
✅ Background info on flaw root causes
✅ Secure development principles for each issue class
The guided testing methodology makes WebGoat the perfect onramp before assessing production systems.
Real-World Banking Application Hacking with JUGS
Eager to apply your web hacking chops in a more realistic context? JUGS is just what you need.
Created by application security researcher Jack Wichere, JUGS (Jack Under the Gun) models an online banking portal with common flaws found in financial institutions. Architected using Python with an SQLite database, JUGS allows safely improving skills against software closer to commercial targets.
The application contains account login, money transfer, and loan request functions with vulnerabilities like:
- SQL injection
- Cross-site scripting
- Logic flaws
- Authentication bypass issues
Exploiting these weaknesses follows real-world hacking progression from initial access to asset theft to covering your tracks. For example, you might:
- Bypass the login form via UNION SQLi attack
- Use stored XSS to steal admin session tokens
- Perform unauthorized money transfers from harvested credentials
- Wipe server logs using shell command injection to erase traces
JUGS provides both a more rigorous technical challenge and important business context around hacking compared to more contrived apps. All wrapped in an engaging scenario to boost learning.
Why JUGS Shines:
✅ Real-world vulnerable banking application modeled after popular targets
✅ Practical hacking progression from access to theft to hiding tracks
✅ Combines technical rigor with crucial business context
✅ Python + SQLite architecture mirrors many modern web apps
Damn Vulnerable Web App (DVWA): Easy Onramp for Major Flaws
Damn Vulnerable Web Application (DVWA) is a prime introductory target for your first vulnerable application experiences.
Written in PHP/MySQL, DVWA offers intentional vulnerabilities across major web risk categories like cross-site scripting, SQL injection, and insecure file upload. Installation only requires setting up PHP + MySQL locally or on a testing server.
DVWA’s genius is in its simplicity geared towards beginners. Security issues are presented across five difficulty levels progressively ramping up complexity. This allows tailoring challenges to your existing skill level before moving to more advanced techniques.
DVWA also conveniently bundles thorough documentation explaining background on vulnerabilities tested alongside references for further learning. The open-source application is feature-packed vulnerability testing out of the box.
DVWA Highlights:
✅ Easy local setup with XAMPP or MAMPP stacks
✅ 5 adjustable difficulty levels to match abilities
✅ Major flaws like XSS, SQLi, and file upload attacks
✅ Extensive bundled docs explain vulnerabilities
If you‘re looking for a quick start with vulnerable app testing, DVWA is the perfect launching pad.
Customizable Vulnerability Testing with Mutillidae
Once comfortable with basic app testing, Mutillidae allows taking your web hacking to the next level.
Maintained by OWASP, Mutillidae II provides a complete vulnerable web application toolkit for penetration testing and security training. Built on PHP, the open source app comes preloaded with over 50 vulnerabilities covering OWASP Top 10 application risks.
Spanning beginner through expert content, the self-contained Mutillidae testbed allows drilling down on specific weaknesses of interest across categories like:
- Injection Attacks
- Broken Authentication
- Sensitive Data Exposure
- XML External Entities Injection
- And more…
With granular payloads and hints, both black box and white box app testing is possible. Code samples even demonstrate secure implementation patterns for reference after you successfully exploit a flaw.
Regularly refreshed by the community, Mutillidae includes some of the most comprehensive application security training content available.
Why Mutillidae Stands Out:
✅ 50+ vulnerabilities covering OWASP Top 10 web risks
✅ Highly customizable app sec testing playground
✅ Black box + white box testing options
✅ Up-to-date vulnerability database maintained by community
✅ Secure code examples for training defense as well
Ready for next-level, full lifecycle training from recon to exploitation and remediation? Mutillidae has you covered.
Only Google could make application security whimsical. Enter Gruyere…
Gruyere guides users through web security education via cheesy coding puzzles and puns. Built in Python, this app leads a mouse named George through block after block of Swiss cheese-themed apps. Each vulnerability exploited earns you a slice of cheese!
The goofy cheese theme makes otherwise dry security concepts approachable for software engineers and quality testers. Underlying each maze is a serious vulnerability like cross-site scripting and a well-designed remediation lesson.
For those looking for a fun break from rigid vulnerable web apps, Gruyere hits the spot for learning. Who said application security can‘t involve fondue?
Gruyere Features:
✅ Whimsical, game-oriented training environment
✅ Lessons on XSS, access control, and code injection
✅ Cheese pun-based guidance and examples
✅ Background on flaw causes built into remediation
🧀🧀🧀
Damn Insecure and Vulnerable App (DIVA): Climbing the SPA Learning Curve
SPA? API? JWT? Learning modern web application hacking requires mastering far more than SQLi these days.
Damn Insecure and Vulnerable App (DIVA) delivers those contemporary web targets and education through its mantra: “Go big or go home!”
DIVA specifically focuses vulnerabilities in complex single page applications (SPAs) and APIs unlike older PHP apps. Training grounds like WebGoat use basic frontends while DIVA prepares you for highly dynamic targets like:
- React
- Angular
- Vue
- Other JS SPA frameworks
And backend API testing requires going beyond basic injections to tackle issues like:
- JWT authentication weaknesses
- Business logic flaws
- Insecure endpoints
- Rate limiting errors
DIVA pushes your skills to handle vulnerable modern web tech stacks serving interactive web and mobile applications.
DIVA’s Advanced Approach:
✅ Single page web apps with React, Angular, and Vue
✅ API hacking using Burp Suite and other tools
✅ UiWebView, JavaScriptCore abuse
✅ Tackling JWT, OAuth, and SSO vulnerabilities
If you’re already a seasoned web hacker, DIVA delivers the next-generation application security challenges to keep skills razor sharp.
Learn JavaScript and Node.js Flaws with NodeGoat
For practitioners working heavily in JavaScript and Node.js, NodeGoat delivers a prime hands-on learning experience.
Maintained by OWASP, NodeGoat is a vulnerable Node.js web app designed specifically to highlight security issues developers face with the runtime. Starting as a small open-source project, NodeGoat has quickly grown into a robust education resource supporting 30+ exercises across risks like:
- Injection attacks
- Authentication weaknesses
- Session management flaws
- Violating security best practices
- And more…
NodeGoat also provides code snippets demonstrating secure implementation of features after you successfully exploit a vulnerability. This aids cementing defensive coding habits in addition to honing your inner hacker.
If your work revolves around JS and Node.js systems, NodeGoat offers invaluable highly specific training for these environments.
Why Specialize Training with NodeGoat:
✅ 30+ JavaScript and Node.js vulnerabilities
✅ Content updated monthly by community
✅ OWASP Top 10 alignment
✅ Secure code examples provided
All-in-One Vulnerable Infrastructure: Web Security Dojo
Many vulnerable standalone applications only focus on a single technology stack. Excellent for specialized practice, but switching between apps to test different languages gets tedious.
For cross-technology training, Web Security Dojo delivers everything in one virtual machine package.
Offered by information security company Maven Security, Web Security Dojo packs multiple intentionally vulnerable web apps like WebGoat alongside hacking tools into an Ubuntu 12.04 desktop VM. Imports easily into VirtualBox or VMware then boots as a full working Ubuntu OS.
Preconfigured utility belts like Burp Suite and Ratproxy proxy tester enable instantly digging into provided vulnerable sites:
- WebGoat
- Webgoat.NET
- Mutillidae
- Peruggia (Maven original)
With multiple built-in apps spanning platforms like Java, .Net, and PHP, this VM allows easily pivoting focus while leveraging a consistent toolkit. Supporting material takes you through working vulnerabilities end-to-end.
Think of the Web Security Dojo as a web hacking multimedia center ready out of the box!
Web Dojo Benefits:
✅ All-in-one Ubuntu desktop virtual machine
✅ Multiple preloaded vulnerable test applications
✅ Burp Suite, Ratproxy, and other tools installed
✅ Step-by-step exercises for hands-on learning
✅ Easy workflow jumping between tech stacks
For folks seeking a versatile but turnkey vulnerable web app sandbox, spin up a Web Dojo.
Leveling Up Your App Testing Game
With this comprehensive guide to prime intentionally vulnerable web apps for honing skills, you‘re equipped to start training like professional penetration testers!
Most important is finding options fitting your experience level then expanding scope against more sophisticated targets over time. Lean into challenges that push your abilities but don‘t get discouraged if advanced techniques seem daunting early on.
Setting up a home testing lab is also invaluable for efficiently improving at your own pace. Using VMs or Docker, you can quickly cycle between multiple apps mixing up vulnerabilities. Look to tools like Web Security Dojo that simplify spinning up integrated environments.
No matter where you‘re starting, dedicating time consistently against these safe targets is what counts. Even spending 30 minutes poking around flawed apps a few days per week will produce tremendous returns over months.
And remember to pay forward your hacking help as you learn! Write-ups explaining interesting vulnerabilities you discover can support the next generation following in your footsteps.
Still hungry to further unlock your web hacking potential? Here are a few parting recommendations:
👉 For Beginners
Start with DVWA or WebGoat for initial experience then expand into realistic targets like JUGS to cement fundamental skills.
👉 For Intermediates
Mix up app frameworks with NodeGoat, Gruyere or Mutillidae fitting your technology stack while gradually increasing technical complexity.
For 👉 Advanced Hackers
Tackle sophisticated modern web apps and APIs with DIVA alongside sandbox testing pre-production code before release. Look for novel issues beyond standard checklist flaws.
Thank you for letting me share my passion for empowering the next generation of ethical hackers like yourself! Feel free to reach out if you have any other questions assembling your application security testing toolkit.
Now go out there and continue honing those cyber talents safely against intentional digital punching bags!
