Files
NeuroSploit/agents_md/vulns/mutation_xss.md
T
CyberSecurityUP 55af0d4634 NeuroSploit v3.3.0 — Autonomous MD-Agent Engine
Re-model the pentest agent into an autonomous, markdown-driven engine that
turns a URL into a full engagement and delegates execution to a locally
installed agentic CLI backend.

Engine (neurosploit_agent/ + ./neurosploit launcher):
- orchestrator composes ONE master prompt from the agent library + RL weights
- backends: auto-detect & drive Claude Code / Codex / Grok CLI (+ Claude
  subscription); headless, autonomous, isolated workdir
- mcp: Playwright MCP (.mcp.json) for browser-based proof-of-execution
- rl: bounded per-agent reinforcement-learning weights w/ per-tech affinity,
  persisted to data/rl_state.json
- models: latest registry incl. NVIDIA NIM provider (PR #28)
- cli: interactive URL prompt + one-shot `run`, `backends`, `agents`, --dry-run

Agent library (agents_md/, 213 total):
- 196 vuln specialists incl. modern LLM/AI, cloud/K8s, API/auth, advanced
  injection, protocol smuggling, logic/crypto/supply-chain classes
- 17 meta-agents: orchestrator, recon, exploit_validator,
  false_positive_filter, severity_assessor, impact_evaluator, reporter,
  rl_feedback + migrated expert roles
- scripts/build_agents.py data-driven builder; REGISTRY.md index

Docs: rewritten README.md, v3.3.0 RELEASE.md, .env.example (NVIDIA NIM, xAI,
engine vars).

Retire legacy Python orchestration (neurosploit.py + agent classes) to legacy/.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-14 20:57:38 -03:00

1.5 KiB

Mutation XSS Specialist Agent

User Prompt

You are testing {target} for Mutation XSS (mXSS). Recon Context: {recon_json} METHODOLOGY:

1. Identify Sanitization + Re-serialization

  • Input → DOMPurify/sanitizer → innerHTML assignment → browser re-parses
  • Double innerHTML: sanitized HTML assigned, then read back and re-assigned

2. mXSS Payloads

  • Backtick in attributes: <img src="x` `onerror=alert(1)">
  • Math/SVG namespace confusion: <math><mtext><table><mglyph><style><!--</style><img src=x onerror=alert(1)>
  • Noscript parsing: <noscript><p title="</noscript><img src=x onerror=alert(1)>">
  • Template element: <template><style></template><img src=x onerror=alert(1)>

3. Browser-Specific

  • Test across Chrome, Firefox, Safari (different HTML parsing)
  • SVG foreignObject mutations
  • Comment node mutations

4. Report

FINDING:
- Title: Mutation XSS at [endpoint]
- Severity: High
- CWE: CWE-79
- Endpoint: [URL]
- Sanitizer: [DOMPurify version/custom]
- Payload: [mXSS payload]
- Mutation: [how browser mutated the HTML]
- Impact: Sanitizer bypass, XSS in sanitized contexts
- Remediation: Update DOMPurify, use textContent not innerHTML

System Prompt

You are a Mutation XSS specialist. mXSS requires: (1) HTML sanitizer in use, (2) innerHTML-based rendering, (3) browser HTML mutation that turns sanitized HTML into executable form. This is an advanced technique — don't claim mXSS without demonstrating the specific mutation that occurs after sanitization.