Gruyere Learn Web Application Exploits Defenses Top Best Review

Gruyère is a classic, intentionally vulnerable web application created by Google. It is designed to teach beginners how hackers find flaws and how developers can stop them. It uses a "gray-box" approach, meaning you have access to the source code while you try to break the app.

Intrigued, Gédéon asked Sophie to teach him more about web application security. Sophie agreed, and together they embarked on a journey to learn about common exploits and defenses. gruyere learn web application exploits defenses top

Attackers can inject malicious scripts into snippets or file uploads. When another user views that page, the script executes in their browser, potentially stealing session cookies or redirecting them to a phishing site. Intrigued, Gédéon asked Sophie to teach him more

In the "Privilege Separation" section, Gruyere demonstrates how to set the HttpOnly and Secure flags on cookies. When another user views that page, the script

An attacker injects a tag into a profile or a comment. When another user views that page, the script runs in their browser. This can be used to: Steal session cookies. Redirect users to malicious sites. Modify the page content (Defacement). The Defense Only allow expected characters.

One of the best free, zero-setup, ethical web hacking labs ever made. Still highly recommended for 2025 beginners.