mcpnuke: Skill for Cursor

Add a New mcpnuke Check

Gather Info

1. Check name — snake_case (e.g. jwt_audience, ssrf_probe)
2. Check type — static (metadata only) or behavioral (calls tools)
3. What it detects — one sentence
4. Severity — CRITICAL / HIGH / MEDIUM / LOW
5. Taxonomy ID — MCP-T## from the playbook (if applicable)

File Locations

mcpnuke/
├── patterns/rules.py          # Static regex patterns
├── patterns/probes.py         # Behavioral probe payloads
├── checks/
│   ├── __init__.py            # run_all_checks() — wire new check here
│   ├── your_check.py          # New check module
│   └── base.py                # time_check helper
├── core/constants.py          # ATTACK_CHAIN_PATTERNS — add chains here
tests/
├── test_your_check.py         # Unit tests
├── test_dvmcp.py              # DVMCP integration tests

Step-by-Step

1. Add patterns (if static check)

Edit mcpnuke/patterns/rules.py:

YOUR_CHECK_PATTERNS = [
    r"pattern_one",
    r"pattern_two",
]

2. Create the check module

Create mcpnuke/checks/your_check.py:

"""Description of what this check detects."""

import re

from mcpnuke.core.models import TargetResult
from mcpnuke.checks.base import time_check
from mcpnuke.patterns.rules import YOUR_CHECK_PATTERNS


def check_your_check(result: TargetResult):
    with time_check("your_check", result):
        for tool in result.tools:
            name = tool.get("name", "")
            combined = (
                name + " "
                + tool.get("description", "")
                + " " + str(tool.get("inputSchema", {}))
            )
            for pat in YOUR_CHECK_PATTERNS:
                if re.search(pat, combined, re.IGNORECASE):
                    result.add(
                        "your_check",
                        "SEVERITY",
                        f"Finding title for tool '{name}'",
                        f"Detail: {pat}",
                        evidence=combined[:300],
                    )
                    break