actions-scanner

name	actions-scanner
description	Scan GitHub Actions workflows for PwnRequest and other CI/CD vulnerabilities. Use when the user wants to scan repositories, organizations, or local directories for GitHub Actions security issues like pull_request_target exploits, context injection, artifact injection, or dispatch checkout vulnerabilities.

GitHub Actions Vulnerability Scanner

A security scanner that detects exploitable patterns in GitHub Actions workflows, focusing on PwnRequest attacks and related CI/CD supply chain vulnerabilities.

Quick Reference

# Scan a single repo
actions-scanner scan owner/repo

# Scan a GitHub org (requires GITHUB_TOKEN)
actions-scanner scan-org myorg

# Scan a local directory
actions-scanner scan ./path/to/repo

# Scan repos from a file (one URL per line)
actions-scanner scan repos.txt

# Clone repos for analysis
actions-scanner clone repos.txt -d repos/

# Generate a markdown report from CSV results
actions-scanner report vulnerabilities.csv --format markdown

# AI-assisted validation of findings
actions-scanner validate vulnerabilities.csv

What It Detects

The scanner identifies 6 vulnerability classes:

Detector	Trigger	Risk
PwnRequest	pull_request_target + untrusted checkout + code execution	Secrets exfiltration via malicious PR
WorkflowRun	workflow_run + artifact injection	Code execution via poisoned artifacts
ContextInjection	${{ }} expressions in run: blocks using attacker-controlled inputs	Arbitrary command injection
ArtifactInjection	Reading artifact content into shell commands	Code execution via crafted artifacts
DispatchCheckout	issue_comment/workflow_dispatch + PR checkout	Code execution via comment-triggered builds
MergedPR	Patterns above but gated on merged PRs	Lower risk, requires merged code

Protection Levels

Each finding is classified by its protection level:

• none - Fully exploitable by any fork PR (critical)
• label - Requires a maintainer to add a label (social engineering vector)
• permission - Requires PR author to have write/admin access
• same_repo - Only triggers for PRs from the same repo, not forks
• actor - Restricted to specific bot actors
• merged - Only runs on already-merged PRs

Commands

scan - Primary Scanner

actions-scanner scan TARGET [OPTIONS]

TARGET accepts: GitHub org name, repo URL (owner/repo or full URL), local directory path, or a file with one target per line.

Key options:

• -o, --output PATH - Output file (default: outputs/vulnerabilities.csv)
• --format csv|json|markdown - Output format (default: csv)
• --no-protected - Exclude permission-gated findings
• --no-labeled - Exclude label-gated findings
• --include-same-repo - Include same-repo-only findings (excluded by default)
• --all-branches - Scan multiple branches via smart sampling
• --max-branches N - Max branches per repo (default: 10)
• --validate - Run AI validation after scanning
• --clone-workers N - Parallel clone workers (default: 5)

scan-org - Organization Scanner

actions-scanner scan-org ORG [OPTIONS]

Discovers all repos in a GitHub organization, clones them with sparse checkout, and scans. Requires GITHUB_TOKEN.

Additional options:

• --org-file PATH - File with newline-separated org names
• --include-forks - Include forked repos
• --include-archived - Include archived repos
• --list-only - List repos without scanning
• --skip-clone - Scan existing clones in output-dir
• -d, --output-dir PATH - Clone destination

validate - AI Validation

actions-scanner validate VULNERABILITIES_FILE [OPTIONS]

Uses an AI agent to confirm or reject findings. Produces per-repo confirmation files (confirmed_vulnerable.txt, confirmed_weakness.txt, not_vulnerable.txt).

Options:

• -d, --repos-dir PATH - Directory containing cloned repos
• --agent TEMPLATE - Custom agent command (e.g., "codex -m gpt-4 -p {}")
• -w, --workers N - Parallel validation workers (default: 5)
• --timeout SECS - Per-repo timeout (default: 300)

clone - Sparse Cloner

actions-scanner clone REPOS_FILE [OPTIONS]

Clones repos with sparse checkout (only .github/ directory) for efficient scanning.

report - Format Converter

actions-scanner report VULNERABILITIES_FILE [OPTIONS]

Converts vulnerability CSV to markdown or JSON.

Common Workflows

Scan a single org and get a markdown report

export GITHUB_TOKEN=ghp_...
actions-scanner scan-org myorg --format markdown -o report.md

Scan multiple orgs from a file

# orgs.txt contains one org name per line
actions-scanner scan-org --org-file orgs.txt -d repos/ -o results.csv

Scan with multi-branch coverage

actions-scanner scan owner/repo --all-branches --max-branches 5

Full pipeline: scan then validate

actions-scanner scan-org myorg -o findings.json --format json
actions-scanner validate findings.json -d /tmp/actions-scanner-*/

Scan a local checkout

git clone https://github.com/org/repo
actions-scanner scan ./repo

Environment Variables

Variable	Purpose
GITHUB_TOKEN	Required for org scanning and API access
ANTHROPIC_API_KEY	Required for AI validation with Claude
ACTIONS_SCANNER_*	Override any config setting (e.g., ACTIONS_SCANNER_SCAN__WORKERS=20)

Configuration

The scanner reads config from .actions-scanner.yaml in the working directory or parents:

scan:
  workers: 10
  sparse_paths: [".github/"]

github:
  concurrency: 50
  timeout: 30

validation:
  command_template: 'claude -p "{}"'
  timeout: 300
  workers: 5

output:
  format: csv
  verbose: false

Output Format

CSV columns: vulnerability_type, org, repo, branch, workflow_path, job_name, checkout_line, checkout_ref, exec_line, exec_type, exec_value, protection, protection_detail

Development

# Install with dev dependencies
uv sync --dev

# Run tests
uv run pytest

# Lint
uv run ruff check src/

# Type check
uv run ty check src/

Project Structure

src/actions_scanner/
  cli/main.py          # CLI entry point (click-based)
  core/
    detector.py        # 6 vulnerability detector classes
    models.py          # VulnerableJob, ScanResult models
    patterns.py        # Regex patterns for dangerous refs/commands
  config/settings.py   # Pydantic settings (YAML, env, CLI)
  git/                 # Sparse cloning, worktrees, multi-branch
  github/              # Async GitHub API client, org scanning
  reporting/           # CSV, JSON, markdown report generators
  validation/          # AI-assisted validation agent
  utils/               # Console, progress, path utilities