---
name: html-injection-testing
source: https://app.decimal.ai/s/html-injection-testing@3/SKILL.md
source_sha256: dface9cc0174
---

> **⚠️ AUTHORIZED USE ONLY**
> This skill is for educational purposes or authorized security assessments only.
> You must have explicit, written permission from the system owner before using this tool.
> Misuse of this tool is illegal and strictly prohibited.

> **Mandatory confirmation gate**
> Before running any command that probes, exploits, changes, persists on, extracts data from, or attempts credential access against a target:
> 1. Ask the user to state the exact target URL, IP, account, or resource.
> 2. Ask the user to confirm written authorization and the permitted scope.
> 3. Show the exact command(s) and explain their expected effect.
> 4. Wait for explicit confirmation in the current conversation.
>
> Without that confirmation, remain read-only and provide defensive guidance only. Prefer a sandbox, disposable VM, or controlled lab.

> AUTHORIZED USE ONLY: Use this skill only for authorized security assessments, defensive validation, or controlled educational environments.

# HTML Injection Testing

## Detailed Guide

Read [the detailed guide](references/detailed-guide.md) before executing this skill. It retains the complete procedure and reference material. Treat its safety, prerequisites, and validation requirements as mandatory. For focused work, load the relevant sections; for end-to-end work, read the guide completely.

## Prerequisites

### Required Tools
- Web browser with developer tools
- Burp Suite or OWASP ZAP
- Tamper Data or similar proxy
- cURL for testing payloads

### Required Knowledge
- HTML fundamentals
- HTTP request/response structure
- Web application input handling
- Difference between HTML injection and XSS

## Constraints and Limitations

### Attack Limitations
- Modern browsers may sanitize some injections
- CSP can prevent inline styles and scripts
- WAFs may block common payloads
- Some applications escape output properly

### Testing Considerations
- Distinguish between HTML injection and XSS
- Verify visual impact in browser
- Test in multiple browsers
- Check for stored vs reflected

### Severity Assessment
- Lower severity than XSS (no script execution)
- Higher impact when combined with phishing
- Consider defacement/reputation damage
- Evaluate credential theft potential

## When to Use
This skill is applicable to execute the workflow or actions described in the overview.