---
name: detecting-supply-chain-attacks-in-ci-cd
description: >
  Scans GitHub Actions workflows and CI/CD pipeline configurations for supply chain
  attack vectors including unpinned actions, script injection via expressions, dependency
  confusion, and secrets exposure. Uses PyGithub and YAML parsing for automated audit.
  Use when hardening CI/CD pipelines or investigating compromised build systems.
domain: cybersecurity
subdomain: security-operations
tags: [detecting, supply, chain, attacks]
version: "1.0"
author: mahipal
license: MIT
---

# Detecting Supply Chain Attacks in CI/CD

## Instructions

Scan CI/CD workflow files for supply chain risks by parsing GitHub Actions YAML,
checking for unpinned dependencies, script injection vectors, and secrets exposure.

```python
import yaml
from pathlib import Path

for wf in Path(".github/workflows").glob("*.yml"):
    with open(wf) as f:
        workflow = yaml.safe_load(f)
    for job_name, job in workflow.get("jobs", {}).items():
        for step in job.get("steps", []):
            uses = step.get("uses", "")
            if uses and "@" in uses and not uses.split("@")[1].startswith("sha"):
                print(f"Unpinned action: {uses} in {wf.name}")
```

Key supply chain risks:
1. Unpinned GitHub Actions (using @main instead of SHA)
2. Script injection via ${{ github.event }} expressions
3. Overly permissive GITHUB_TOKEN permissions
4. Third-party actions with write access to repo
5. Dependency confusion via public/private package name collision

## Examples

```python
# Check for script injection in run steps
for step in job.get("steps", []):
    run_cmd = step.get("run", "")
    if "${{" in run_cmd and "github.event" in run_cmd:
        print(f"Script injection risk: {run_cmd[:80]}")
```