Skills

Hunt HTML Injection

Hunt HTML Injection, user-supplied input is rendered as raw HTML in the response...

Install

npx skills add elementalsouls/Claude-BugHunter --skill hunt-html-injection -g -a claude-code -y
Category
Design
Updated
3d ago
License
MIT
Context cost
Lightabout 952 tokens
Runs scripts
No, instructions only

What it does

Hunt HTML Injection, user-supplied input is rendered as raw HTML in the response without sanitisation, allowing an attacker to inject arbitrary HTML tags (but not necessarily JavaScript). Lower severity than XSS but enables phishing, UI manipulation, and credential harvesting via injected forms. Use when testing text-display surfaces (search results, profile fields, comments, error messages, feedback forms). For markup that executes JavaScript, escalate to hunt-xss.

What is HTML Injection

HTML Injection occurs when user input is inserted into a page's HTML without escaping, so injected tags are rendered by the browser as markup rather than displayed as literal text. Unlike XSS, the injected content does not require JavaScript execution, injecting <b>, <h1>, <a>, <img>, or <form> tags is sufficient.

To PROVE impact unambiguously, escalate to an active vector carrying a unique numeric canary, e.g. "><img src=x onerror=alert(91234)> or <svg onload=alert(91234)>. A distinctive 4+ digit number (not alert(1)) distinguishes YOUR reflected injection from the example payloads practice pages embed in their own hint text. Proof = the raw, unescaped vector with your canary appears in the response.

Read the whole SKILL.md on GitHub

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