Medusa Security Skill Skill

Medusa Security Skill

Identity

AI-first security scanner integration skill. Leverages Medusa's 76 scanners and 3,000+ detection patterns for comprehensive security analysis including AI/ML-specific vulnerability detection.

Capabilities

Full Scan — All 76 scanners, comprehensive security analysis
AI-Only Scan — Prompt injection, MCP security, agent security, RAG security
Quick Scan — Git-changed files only for rapid development feedback
Targeted Scan — Specific scanner categories (mcp, secrets, prompt-injection, etc.)
SARIF Output Parsing — Standard SARIF v2.1.0 structured findings
JSON Output Parsing — Medusa-native JSON format
OWASP Mapping — Maps findings to OWASP Agentic AI (ASI01-10) and OWASP Top 10 (A01-10)
Remediation Guidance — Links findings to agent-studio skills and agents
CI/CD Integration — Fail-on thresholds, SARIF upload for GitHub Code Scanning

Prerequisites

Python 3.10+
pip install medusa-security

Check installation: python -m medusa --version

Workflow: Full Security Scan

# Step 1: Verify installation
python -m medusa --version

# Step 2: Run scan
medusa scan . --format sarif --fail-on high

# Step 3: Parse output (use scripts/main.cjs)
node .claude/skills/medusa-security/scripts/main.cjs --mode full --target .

# Step 4: Review findings by severity
# CRITICAL → immediate fix required
# HIGH → fix before release
# MEDIUM → fix in next sprint
# LOW → track and address

Workflow: AI-Only Scan

medusa scan . --format sarif --ai-only

Scans only: prompt injection (800+ patterns), MCP security (400+ patterns), agent security (500+ patterns), RAG security (300+ patterns).

Workflow: Quick Scan (Development)

medusa scan . --format sarif --quick

Only scans git-changed files. Use during development for rapid feedback.

Workflow: Targeted Scan

# MCP security only
medusa scan . --format sarif --scanners mcp-server,mcp-config

# Secrets only
medusa scan . --format sarif --scanners secrets,gitleaks,env

# AI context files only
medusa scan . --format sarif --scanners ai-context

Output Processing

The skill uses helper scripts located at .claude/skills/medusa-security/scripts/:

| Script | Purpose | | ----------------------- | ----------------------------------------------- | | sarif-parser.cjs | Parses SARIF v2.1.0 output | | json-parser.cjs | Parses Medusa JSON output | | finding-formatter.cjs | Formats findings with OWASP mapping | | main.cjs | Orchestrates the full pipeline | | cli-wrapper.cjs | Wraps Medusa CLI invocation | | security-review.cjs | Deterministic report writer (no Glob recursion) |

Using the Pipeline

# Full scan with structured output
node .claude/skills/medusa-security/scripts/main.cjs --mode full --target .

# AI-only scan
node .claude/skills/medusa-security/scripts/main.cjs --mode ai-only --target .

# Quick scan (git-changed files)
node .claude/skills/medusa-security/scripts/main.cjs --mode quick --target .

Deterministic Security Review (Recommended in Claude sessions)

Use this when you need the final security review report and want to avoid recursive Glob timeouts:

node .claude/skills/medusa-security/scripts/security-review.cjs

This writes:

/.claude/context/reports/security/security-review-medusa-scan-2026-02-17.md

and performs fixed-path checks on:

.claude/hooks/
.claude/lib/
.claude/skills/medusa-security/scripts/
.claude/CLAUDE.md

Important Runtime Guardrail

Avoid recursive glob patterns like .claude/skills/medusa-security/**/* in long sessions.
Prefer direct file reads and deterministic script entry points.

OWASP Mapping

Findings are automatically mapped to:

OWASP Agentic AI Top 10 (ASI01-10): Goal Hijacking, Tool Misuse, Context Poisoning, etc.
OWASP Top 10 (A01-10): Broken Access Control, Injection, Cryptographic Failures, etc.

Severity Triage

| Severity | Action | Timeline | | -------- | ------------------ | ---------------- | | CRITICAL | Immediate fix | Before any merge | | HIGH | Fix before release | Same sprint | | MEDIUM | Fix in next sprint | Next cycle | | LOW | Track and address | Backlog |

Agent Integration

| Agent | Usage | | -------------------- | ----------------------------------------------------------- | | security-architect | Primary consumer. Use for comprehensive security reviews. | | penetration-tester | Use for targeted vulnerability scanning with authorization. | | code-reviewer | Use AI-only scan as part of code review workflow. |

CI/CD Integration

# GitHub Actions example
- name: Security Scan
  run: |
    pip install medusa-security
    medusa scan . --format sarif --fail-on high -o reports/
- name: Upload SARIF
  uses: github/codeql-action/upload-sarif@v3
  with:
    sarif_file: reports/medusa-results.sarif

Iron Laws

ALWAYS verify Medusa installation before scanning — python -m medusa --version first; a missing install produces no output instead of an error, silently masking all vulnerabilities.
NEVER rely on AI-only mode as the release gate — AI-only mode misses traditional SAST patterns (SQLi, XSS, path traversal); full scan covering all 76 scanners is required for release-gate decisions.
ALWAYS set --fail-on high in CI/CD pipelines — without a fail threshold, pipelines pass even when CRITICAL findings exist, creating false confidence in the security posture.
NEVER skip SARIF upload to GitHub Code Scanning — local-only SARIF is lost after the build; uploading via github/codeql-action/upload-sarif@v3 persists findings for PR review, trend tracking, and compliance audit trails.
ALWAYS fix CRITICAL and HIGH findings before merging — deploying with unresolved high-severity findings expands the attack surface and nullifies the security posture gain from scanning.

Anti-Patterns

| Anti-Pattern | Why It Fails | Correct Approach | | ------------------------------------ | ----------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------- | | Skipping installation check | Missing Medusa produces no output, not an error — all vulnerabilities silently missed | Run python -m medusa --version first; abort on non-zero exit | | Using AI-only mode as a release gate | AI-only misses traditional SAST patterns (SQLi, XSS, path traversal) — 76 scanners needed for full coverage | Use full-scan mode for CI/CD gates; AI-only mode for rapid dev-time feedback only | | No fail-on threshold in CI | Pipeline passes even when CRITICAL findings exist — false confidence in security posture | Always use --fail-on high in CI pipelines; adjust to --fail-on critical for high-risk repos | | Ignoring MEDIUM findings | MEDIUM findings compound into exploitable chains when combined with HIGH findings | Triage MEDIUM findings each sprint; never allow them to accumulate without a tracking issue | | Not uploading SARIF to Code Scanning | Findings live only in local files, lost after build — no PR-level review or trend tracking | Upload SARIF via github/codeql-action/upload-sarif@v3 in every CI run |

Memory Protocol

After scanning:

Record new vulnerability patterns in patterns.json
Log significant findings in issues.md
Track scan history for trend analysis
Use recordGotcha() for recurring false positives

const manager = require('.claude/lib/memory/memory-manager.cjs');

manager.recordGotcha({
  text: 'False positive: medusa flags X pattern in Y context',
  area: 'security-scanning',
});

manager.recordPattern({
  text: 'Prompt injection found in CLAUDE.md context files',
  area: 'ai-security',
});

Related Skills

security-architect — Threat modeling and OWASP analysis
static-analysis — CodeQL and Semgrep SARIF analysis
semgrep-rule-creator — Create custom Semgrep rules
insecure-defaults — Detect hardcoded credentials
variant-analysis — Discover vulnerability variants

Agent Skills: Medusa Security Skill

Install this agent skill to your local

Skill Files