Using GitHub's security features to secure your use of GitHub Actions

About GitHub's security features

GitHub provides many features to make your code more secure. You can use GitHub's built-in features to understand the actions your workflows depend on, ensure you are notified about vulnerabilities in the actions you consume, or automate the process of keeping the actions in your workflows up to date. If you publish and maintain actions, you can use GitHub to communicate with your community about vulnerabilities and how to fix them. For more information about security features that GitHub offers, see GitHub セキュリティ機能.

This article will explain how you can use some of GitHub's security features to increase the security of your use of GitHub Actions.

Understanding dependencies in your workflows

You can use the dependency graph to explore the actions that the workflows in your repository use. The dependency graph is a summary of the manifest and lock files stored in a repository. It also recognizes files in ./github/workflows/ as manifests, which means that any actions or workflows referenced using the syntax jobs[*].steps[*].uses or jobs.<job_id>.uses will be parsed as dependencies.

The dependency graph shows the following information about actions used in workflows:

• The account or organization that owns the action.
• The workflow file that references the action.
• The version or SHA the action is pinned to.

In the dependency graph, dependencies are automatically sorted by vulnerability severity. If any of the actions you use have security advisories, they will display at the top of the list. You can navigate to the advisory from the dependency graph and access instructions for resolving the vulnerability.

The dependency graph is enabled for public repositories, and you can choose to enable it on private repositories. For more information about using the dependency graph, see リポジトリの依存関係を調べる.

Being aware of security vulnerabilities in actions you use

For actions available on the marketplace, GitHub reviews related security advisories and then adds those advisories to the GitHub Advisory Database. You can search the database for actions that you use to find information about existing vulnerabilities and instructions for how to fix them. To streamline your search, use the GitHub Actions filter in the GitHub Advisory Database.

You can set up your repositories so that you:

• Receive alerts when actions used in your workflows receive a vulnerability report. For more information, see Monitoring the actions in your workflows.
• Are warned about existing advisories when you add or update an action in a workflow. For more information, see Screening actions for vulnerabilities in new or updated workflows.

Monitoring the actions in your workflows

You can use Dependabot to monitor the actions in your workflows and enable Dependabot alerts to notify you when an action you use has a reported vulnerability. Dependabot performs a scan of the default branch of the repositories where it is enabled to detect insecure dependencies. Dependabot generates Dependabot alerts when a new advisory is added to the GitHub Advisory Database or when an action you use is updated.

You can enable Dependabot alerts for your personal account, for a repository, or for an organization. For more information, see Dependabot アラートの構成.

リポジトリのDependabot alertsタブの開いた・閉じたすべてのDependabot alertsおよび対応するDependabot security updatesを表示できます。 For more information, see Dependabot アラートの表示と更新.

Screening actions for vulnerabilities in new or updated workflows

When you open pull requests to update your workflows, it is good practice to use dependency review to understand the security impact of changes you've made to the actions you use. 依存関係レビューを使うと、すべてのPull Reqeustにおける以下の変更による依存関係の変化とセキュリティについての影響を理解しやすくなります。pull request の [Files Changed](変更されたファイル) タブ上のリッチ diff で依存関係の変更をわかりやすく視覚化できます。 依存関係レビューは、以下のことを知らせます:

• リリース日と合わせて、追加、削除、更新された依存関係
• これらのコンポーネントを使うプロジェクトの数
• これらの依存関係に関する脆弱性のデータ

If any of the changes you made to your workflows are flagged as vulnerable, you can avoid adding them to your project or update them to a secure version.

For more information about dependency review, see 依存関係の確認について.

"依存関係レビュー アクション" とは、GitHub Actions コンテキスト内の pull request の差異を報告できる特定のアクションです。 以下を参照してください。dependency-review-action リポジトリで 依存関係レビュー アクション を使って、pull request に依存関係レビューを適用できます。 このアクションは、pull request のパッケージ バージョンの変更によって発生した依存関係の脆弱なバージョンをスキャンし、関連するセキュリティの脆弱性について警告します。 これにより、pull request で何が変更されているかをより正確に把握でき、リポジトリに脆弱性が追加されるのを防ぐことができます。 For more information, see 依存関係の確認について.

Keeping the actions in your workflows secure and up to date

リポジトリで使用されるアクションおよび再利用可能なワークフローのリファレンスを常に最新の状態に保つため、Dependabotを使用できます。 多くの場合、アクションはバグ修正および新しい機能で更新され、自動化プロセスの速度、安全性、信頼性が向上しています。 Dependabotは、依存関係の保守を自動的に実行するため、作業量が軽減されます。 詳細については、「Dependabot でアクションを最新に保つ」および「Dependabot のセキュリティ アップデート」を参照してください。

The following features can automatically update the actions in your workflows.

• Dependabot version updates open pull requests to update actions to the latest version when a new version is released.
• Dependabot security updates open pull requests to update actions with reported vulnerabilities to the minimum patched version.

For information on how to configure Dependabot version updates, see Dependabot のバージョン アップデートの設定.

For information on how to configure Dependabot security updates, see Configuring Dependabot security updates (Dependabot セキュリティ アップデートの構成).

Protecting actions you've created

GitHub enables collaboration between people who publish and maintain actions and vulnerability reporters in order to promote secure coding. リポジトリ セキュリティ アドバイザリを使用すると、パブリック リポジトリのメンテナーは、プロジェクト内のセキュリティの脆弱性について非公開で話し合い、修正することができます。 共同で修正を行った後、リポジトリ保守担当者はセキュリティ アドバイザリを公開して、セキュリティの脆弱性をプロジェクトのコミュニティに開示することができます。 セキュリティ アドバイザリを公開することにより、リポジトリ保守担当者は、コミュニティがいっそう簡単にパッケージの依存関係を更新したり、セキュリティの脆弱性の影響を調べたりできるようにします。

If you are someone who maintains an action that is used in other projects, you can use the following GitHub features to enhance the security of the actions you've published.

• Use the dependants view in the Dependency graph to see which projects depend on your code. If you receive a vulnerability report, this will give you an idea of who you need to communicate with about the vulnerability and how to fix it. For more information, see リポジトリの依存関係を調べる.
• Use repository security advisories to create a security advisory, privately collaborate to fix the vulnerability in a temporary private fork, and publish a security advisory to alert your community of the vulnerability once a patch is released. For more information, see リポジトリのプライベート脆弱性レポートの構成 and リポジトリ セキュリティ アドバイザリの作成.