Tainted: Code Security Quiz

Spot the bug. Learn the fix. Tainted is a quick-fire code review game for developers. Read a short code example, tap the lines you think are vulnerable, and find out right away whether you were right, why it matters, and how to fix it. PRACTICE THE WAY REAL REVIEWS WORK Some examples hide a real vulnerability. Others are perfectly safe. Recognizing safe code is part of the challenge, so every example has a "No vulnerability" answer. LEARN FROM EVERY ANSWER • A clear explanation of what is wrong, with the weakness category and CWE reference. • A practical fix you can apply to your own code. • A review of every example you missed at the end of each round. BUILT FOR DEVELOPERS • Almost 500 examples in JavaScript, Python, Java, Go, C, PHP, and Solidity. • Choose the languages you work in, or practice all of them. • Rounds of ten examples against the clock, getting harder as you advance. • Covers injection, cross-site scripting, broken access control, weak cryptography, memory safety, race conditions, smart contract flaws, and more. • Scores, streaks, and accuracy by topic show which weaknesses need more practice. PRIVATE AND SIMPLE Works offline. No account, no ads, no in-app purchases, and no tracking. Your progress stays on your device. Tainted is a learning tool for developers. Examples are displayed as text and are never executed.