Break Filter JS from HTML

About

This skill equips developers and security researchers with a robust framework for analyzing HTML sanitization mechanics and discovering potential bypass vectors. It guides users through a multi-phase process including environment reconnaissance, parser differential analysis, and systematic verification of XSS payloads. Whether tackling CTF challenges or performing authorized penetration testing, it ensures a methodical approach to bypassing filters by exploiting how different browsers and server-side libraries interpret complex HTML structures.

Key Features

• Systematic analysis of filter mechanics and parsing library behaviors
• Robust verification protocols to ensure solution stability and idempotency
• Strategic selection of encoding, obfuscation, and DOM clobbering techniques
• Identification of parser differentials between server-side filters and browsers
• 16 GitHub stars
• Implementation patterns for SVG, MathML, and RCDATA context bypasses

Use Cases

• Performing authorized security testing on web application input sanitizers
• Investigating parser differentials for security research and patch verification
• Solving CTF challenges involving complex XSS filter evasion