Exercises

Exercise Avg. Time Difficulty Solved by Tier
JS Sandbox: vm.runInNewContext Null Prototype
This exercise covers escaping vm.runInNewContext when the context is created with Object.create(null) so this.constructor is undefined.
< 1 Hr. medium 35 PRO
JS Sandbox: static-eval Function Property Blocked
This exercise covers bypassing post-2.0 static-eval that blocks member access on functions, using anonymous function bodies.
< 1 Hr. medium 34 PRO
CVE-2026-XX242
This challenge covers the review of a CVE in a python codebase and its patch
< 1 Hr. hard 71 PRO
CVE-2026-XX738
This challenge covers the review of a CVE in a python codebase and its patch
< 1 Hr. hard 69 PRO
Web Fundamentals: Introduction < 1 Hr. hard 291 PRO
JS Sandbox: vm.runInNewContext Empty Context
This exercise covers escaping Node.js vm.runInNewContext with an empty sandbox object via the constructor chain.
medium 37 PRO
JS Sandbox: Type Confusion Bypass
This exercise covers bypassing string sanitization by sending an object when the sanitizer expects a string.
< 1 Hr. medium 39 PRO
JS Sandbox: Regex Filter Bypass
This exercise covers bypassing regex filters with hex escapes, unicode escapes, or base64 decoding.
< 1 Hr. medium 43 PRO
JS Sandbox: AST-Based Filtering
This exercise covers bypassing AST-based sandbox filtering using computed property access or Reflect.get().
medium 40 PRO
CVE-2026-XX822
This challenge covers the review of a CVE in a typescript codebase and its patch
< 1 Hr. hard 73 PRO
CVE-2024-X7X95
This challenge covers the review of a CVE in a JavaScript codebase and its patch
< 1 Hr. hard 56 PRO
CVE-2026-XX292
This challenge covers the review of a CVE in a typescript codebase and its patch
hard 70 PRO
CVE-2026-XX27
This challenge covers the review of a CVE in a javascript codebase and its patch
hard 66 PRO
CVE-2025-XXXXX
This challenge covers the review of a CVE in a JavaScript codebase and its patch
< 1 Hr. hard 62 PRO
Web Fundamentals: Virtual Hosts < 1 Hr. hard 168 PRO
Web Fundamentals: Content Delivery Network < 1 Hr. hard 160 PRO
Web Fundamentals: URL Parsing < 1 Hr. hard 285 PRO
Web Fundamentals: HTTP < 1 Hr. hard 243 PRO
Web Fundamentals: Cookies < 1 Hr. hard 191 PRO
Web Fundamentals: JSON < 1 Hr. hard 185 PRO
Web Fundamentals: HTML < 1 Hr. hard 230 PRO
Web Fundamentals: URL Encoding < 1 Hr. hard 257 PRO
Web Fundamentals: HTML Forms < 1 Hr. hard 207 PRO
JS Sandbox: The Function Constructor
This exercise covers using Function(...)() as an eval alternative to execute arbitrary code in an app that blocks eval.
< 1 Hr. easy 53 PRO
JS Sandbox: From Sandbox Escape to RCE
This exercise covers the standard Node.js RCE chain: process -> mainModule -> require('child_process') -> execSync.
< 1 Hr. easy 54 PRO
JS Sandbox: Keyword Blocklist Bypass
This exercise covers bypassing indexOf/includes blocklists with bracket notation and string concatenation.
< 1 Hr. medium 48 PRO
JS Sandbox: Prototype Chain Navigation
This exercise covers navigating __proto__, .constructor, and .prototype from a string literal to reach the Function constructor.
< 1 Hr. easy 61 PRO
CVE-2026-XX230
This challenge covers the review of a CVE in a python codebase and its patch
< 1 Hr. hard 85 PRO
CVE-2026-XX762
This challenge covers the review of a CVE in a python codebase and its patch
< 1 Hr. hard 85 PRO
CVE-2026-XX977
This challenge covers the review of a CVE in a python codebase and its patch
< 1 Hr. hard 91 PRO
‹ 1 … 2 3 4 5 6 7 8 … 29 ›
Showing 121–150 of 851 exercises