ActionSieve

Note: ActionSieve is under active development and testing. APIs, output formats, and detection behavior are subject to change.

Multi-platform CI/CD pipeline security scanner. Finds injection vulnerabilities, supply chain risks, and misconfigurations across 10 CI/CD platforms using a pattern-driven detection engine.

Features

• Security scanning — pattern-driven detection of expression injection, dangerous triggers, secret exposure, privilege escalation, cache poisoning, and hardening gaps
• Actions Bill of Materials (ABOM) — inventory every external action, orb, pipe, and plugin across your pipelines with actionsieve inventory
• Supply chain analysis — trust scoring for components, SHA pin verification, and advisory database checks against known-compromised dependencies
• Cross-step data flow — taint propagation through GITHUB_OUTPUT, matrix injection, and composite action output laundering
• Forge-wide search — scan an entire GitHub org or GitLab group for vulnerable CI/CD patterns with actionsieve search
• PR-aware scanning — diff-aware mode filters and elevates findings based on what changed, with auto-detection in CI environments
• Multiple output formats — JSON, YAML, SARIF, Markdown, OCSF, and CycloneDX SBOM
• 10 CI/CD platforms — GitHub Actions, GitLab CI, Azure Pipelines, Jenkins, CircleCI, Bitbucket, Buildkite, Drone, CodeBuild, Cloud Build

What it detects

• Expression injection — untrusted PR/issue data interpolated into shell commands via ${{ }}, $CI_*, or platform equivalents
• Supply chain risks — unpinned action/orb/pipe/plugin refs, mutable tags, known-compromised components (advisory database)
• Dangerous triggers — pull_request_target with head checkout, issue_comment with fork access, and platform equivalents
• Secret exposure — static cloud credentials where OIDC is available, secrets logged or leaked through env vars
• Privilege escalation — Docker-in-Docker on shared runners, socket mounts, privileged containers
• Cross-step data flow — taint propagation through GITHUB_OUTPUT, matrix injection, composite action output laundering
• Cache poisoning — cache writes reachable from fork PRs
• Hardening gaps — missing permissions: blocks, checkout with persisted credentials, unpinned container images

Supported platforms

Platform	Provider	Detection
GitHub Actions	github	Workflows, composite actions, reusable workflows
GitLab CI	gitlab	.gitlab-ci.yml, includes, CI variables
Azure Pipelines	azure	YAML pipelines, template expressions
Jenkins	jenkins	Declarative + scripted pipelines (tree-sitter Groovy AST)
CircleCI	circleci	Config, orbs, dynamic config
Bitbucket Pipelines	bitbucket	Pipelines, pipes, deployment variables
Buildkite	buildkite	Pipeline YAML, plugins, dynamic upload
Drone CI	drone	Pipeline YAML, plugins
AWS CodeBuild	codebuild	buildspec.yml, IAM/secret misconfig
Google Cloud Build	cloudbuild	cloudbuild.yaml, service account config

Platform is auto-detected from repository structure. Use --platform to force a specific one.

Install

pip install actionsieve

Or for development:

git clone https://github.com/OpenSecBench/ActionSieve.git
cd ActionSieve
uv sync --dev
pre-commit install

Requires Python 3.12+.

Quick start

# Scan a repository for security issues
actionsieve scan --patterns patterns/ .

# Output as SARIF for GitHub Code Scanning
actionsieve scan --patterns patterns/ --format sarif --output results.sarif .

# Generate an Actions Bill of Materials (ABOM)
actionsieve inventory .

# ABOM with trust scores and advisory checks
actionsieve inventory --online --check .

# Export ABOM as CycloneDX SBOM
actionsieve inventory --format cyclonedx .

Patterns

Security scanning requires a pattern catalog — YAML files that define what to detect. Patterns are maintained separately from the scanner so teams can use community patterns, private patterns, or both. The inventory command works without patterns.

Community patterns: ActionSieve-corpus

# Point to your patterns directory
actionsieve scan --patterns path/to/patterns .

# Or set the environment variable
export ACTIONSIEVE_PATTERNS=path/to/patterns
actionsieve scan .

# Inspect a pattern's full description, attack scenario, and mitigations
actionsieve explain --patterns patterns/ expr-injection-run

Scanning modes

Static mode (default)

Scans all pipeline files at a point in time. Every pattern fires based on what's in the definitions. This is the default when running locally.

actionsieve scan --patterns patterns/ .

PR mode (diff-aware)

Scans in the context of a specific change. Findings are filtered or elevated based on which files changed in the PR. Auto-activates in CI environments where trigger and base ref can be detected.

# Explicit changed files
actionsieve scan --patterns patterns/ --changed-files "Dockerfile,src/app.py" .

# From git diff output
git diff --name-only origin/main | actionsieve scan --patterns patterns/ --changed-files - .

# Context file (for scripted/corpus use)
actionsieve scan --patterns patterns/ --context context.yaml .

# Force mode
actionsieve scan --patterns patterns/ --mode pr --changed-files "Dockerfile" .
actionsieve scan --patterns patterns/ --mode static .    # disable auto-detection in CI

In PR mode, patterns declare how they interact with the changeset:

• Suppress — finding hidden when no relevant file is in the changeset
• Elevate — severity bumped when a relevant file IS in the changeset
• Always — fires identically regardless of changeset (default)

CI auto-detection works for GitHub Actions, GitLab CI, Azure Pipelines, Jenkins, CircleCI, Bitbucket Pipelines, Buildkite, and Drone.

Incremental scanning

Scan only pipeline files changed since a git ref:

actionsieve scan --patterns patterns/ --changed-since main .

This is orthogonal to PR mode — it controls which pipeline files enter the scanner, not how findings are filtered.

Output formats

Format	Flag	Use case
JSON	--format json	Default, machine-readable
YAML	--format yaml	Human-readable
SARIF	--format sarif	GitHub/Azure Code Scanning integration
Markdown	--format markdown	Reports, PR comments
OCSF	--format ocsf	GRC platform integration (Detection Finding 2004)
CycloneDX	--format cyclonedx	ABOM/SBOM export (inventory command)

Environment profiles

Profiles adjust severity based on deployment context. A finding on a public repo with self-hosted runners is more severe than the same finding on a private repo with ephemeral runners.

# Built-in presets
actionsieve scan --patterns patterns/ --profile hosted-public .
actionsieve scan --patterns patterns/ --profile self-hosted .
actionsieve scan --patterns patterns/ --profile hardened .

# Custom profile file
actionsieve scan --patterns patterns/ --profile my-profile.yml .

# See effective profile after resolution
actionsieve profile resolve --profile hosted-public

Profiles can suppress categories, elevate patterns, and extend presets.

Actions Bill of Materials (ABOM)

Generate a complete inventory of every external CI/CD component — actions, orbs, pipes, plugins — across all pipelines in a repository. No patterns required.

# Basic inventory
actionsieve inventory .

# With trust scores and SHA pin verification
actionsieve inventory --online .

# Check components against the advisory database
actionsieve inventory --online --check .

# Export as CycloneDX SBOM
actionsieve inventory --format cyclonedx --output sbom.json .

Each component includes its ref type (SHA, tag, branch), pin status, first-party classification, and locations where it's used. Online mode adds trust scores and verifies that pinned SHAs match their claimed repositories.

Online checks

Verify that SHA-pinned actions actually point to the claimed repository:

actionsieve scan --patterns patterns/ --online .
actionsieve inventory --online --check .

Reads GITHUB_TOKEN from the environment, or pass --token.

Forge search

Search an organization's repositories for vulnerable CI/CD patterns:

# Scan all repos in an org
actionsieve search my-org --patterns patterns/ --forge github

# Targeted pattern search
actionsieve search --pattern expr-injection-run --patterns patterns/ --forge github

# GitLab group
actionsieve search my-group --patterns patterns/ --forge gitlab --token $GITLAB_TOKEN

CI integration

• GitHub Actions — ActionSieve-action (composite action with SARIF upload to Code Scanning)
• GitLab CI / Azure Pipelines — template examples in the action repo

PR mode auto-activates in CI — no configuration needed.

Corpus testing

Run detection patterns against a test corpus to validate accuracy:

# Run all corpus cases
actionsieve corpus run corpus/ --verbose

# Generate a coverage report
actionsieve corpus table corpus/

Exit codes

Code	Meaning
0	No findings (or all suppressed)
1	Findings at medium severity or above (or above --fail-on threshold)
2	Critical findings

Contributing

See CONTRIBUTING.md for development setup and guidelines.

License

MIT