Agent skill · security · davila7
Cross-Site Scripting and HTML Injection Testing
This skill should be used when the user asks to "test for XSS vulnerabilities", "perform cross-site scripting attacks", "identify HTML injection flaws", "exploit client-side injection vulnerabilities", "steal cookies via XSS", or "bypass content security policies". It provides comprehensive techniques for detecting, exploiting, and understanding XSS and HTML injection attack vectors in web applications.
Why this skill is useful
Provides specific techniques and payloads for detecting and exploiting XSS vulnerabilities that the AI wouldn't reliably generate on its own.
What it needs
Requires burp suite installed locally. About 6k tokens when loaded. Last updated 2026-08-06. 30,138 stars on the source repository.
What this skill does
Cross-Site Scripting and HTML Injection Testing Purpose Execute comprehensive client-side injection vulnerability assessments on web applications to identify XSS and HTML injection flaws, demonstrate exploitation techniques for session hijacking and credential theft, and validate input sanitization and output encoding mechanisms. This skill enables systematic detection and exploitation across stored, reflected, and DOM-based attack vectors. Inputs / Prerequisites Required Access Target web application URL with user input fields Burp Suite or browser developer tools for request analysis Access to create test accounts for stored XSS testing Browser with JavaScript console enabled Technical Requirements Understanding of JavaScript execution in browser context Knowledge of HTML DOM structure and manipulation Familiarity with HTTP request/response headers Understanding of cookie attributes and session management Legal Prerequisites Written authorization for security testing Defined scope including target domains and features Agreement on handling of any captured session data Incident response procedures established Outputs / Deliverables XSS/HTMLi vulnerability report with severity classifications Proof-of-concept payloads demonstrating impact Session hijacking demonstrations (controlled environment) Remediation recommendations with CSP configurations Core Workflow Phase 1: Vulnerability Detection Identify Input Reflection Points Locate areas where user input is reflected in responses: Basic Detection Testing Insert test strings to observe application behavior: Monitor for: Raw HTML reflection without encoding Partial encoding (some characters escaped) JavaScript execution in browser console DOM modifications visible in inspector Determine XSS Type Stored XSS Indicators: Input persists after page refresh Other users see injected content Content stored in database/filesystem Reflected XSS Indicators: Input appears only in current response Requires victim to click crafted …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills davila7/xss-html-injection