GH-500 GitHub Advanced Security Exam Question and Answers

In a dependabot.yml configuration file, package-ecosystem is a required key. It defines the package manager being used in that update configuration (e.g., npm, pip, maven, etc.).

Without this key, Dependabot cannot determine how to analyze or update dependencies. Other keys like rebase-strategy or commit-message are optional and used for customizing behavior.

Comprehensive and Detailed Explanation:

To generate a dependency graph for a private repository, GitHub requires:​

Dependency graph enabled: The repository must have the dependency graph feature enabled. This can be configured at the organization level to apply to all new private repositories.​

Access to manifest and lock files: GitHub needs read-only access to the repository's dependency manifest and lock files (e.g., package.json, requirements.txt) to identify and map dependencies.​

You should dismiss a code scanning alert if the flagged code is not a true security concern, such as:

Code in test files

Code paths that are unreachable or safe by design

False positives from the scanner

Fixing the code would automatically resolve the alert — not dismiss it. Dismissing is for valid exceptions or noise reduction.

When using a SARIF-compatible tool within GitHub Actions, it's necessary to explicitly add a step in your workflow to upload the analysis results. This is typically done using the upload-sarif action, which takes the SARIF file generated by your tool and uploads it to GitHub for processing and display in the Security tab. Without this step, the results won't be available in GitHub's code scanning interface.​

Comprehensive and Detailed Explanation:

For code scanning to be triggered on a specific branch, the branch must contain the appropriate workflow file, typically located in the .github/workflows directory. This YAML file defines the code scanning configuration and specifies the events that trigger the scan (e.g., push, pull_request).​

Without the workflow file in the branch, GitHub Actions will not execute the code scanning process for that branch. The repository's visibility (private or public), the status of secret scanning, or the activity level of developers do not directly influence the triggering of code scanning.​

The Security tab in a GitHub repository provides a central location for viewing security-related information, especially when GitHub Advanced Security is enabled. The following can be accessed:

Number of alerts related to:

Code scanning

Secret scanning

Dependency (Dependabot) alerts

Summary and visibility into open, closed, and dismissed security issues.

It does not show 2FA options, access control settings, or configuration panels for GHAS itself. Those belong to account or organization-level settings.

Comprehensive and Detailed Explanation:

To receive Dependabot alert notifications for a repository, you can utilize the following Watch settings:

Custom setting: Allows you to tailor your notifications, enabling you to subscribe specifically to security alerts, including those from Dependabot.​

All Activity setting: Subscribes you to all notifications for the repository, encompassing issues, pull requests, and security alerts like those from Dependabot.​

The Participating and @mentions setting limits notifications to conversations you're directly involved in or mentioned, which may not include security alerts. The Ignore setting unsubscribes you from all notifications, including critical security alerts.​

GitHub Docs

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GitHub Docs

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The correct place to look is the SECURITY.md file. This file provides contributors and security researchers with instructions on how to responsibly report vulnerabilities. It may include contact methods, preferred communication channels (e.g., security team email), and disclosure guidelines.

This file is considered a GitHub best practice and, when present, activates a “Report a vulnerability” button in the repository’s Security tab.

Comprehensive and Detailed Explanation:

Before defining a custom pattern for secret scanning in a repository, you must enable secret scanning for that repository. Secret scanning must be active to utilize custom patterns, which allow you to define specific formats (using regular expressions) for secrets unique to your organization.​

Once secret scanning is enabled, you can add custom patterns to detect and prevent the exposure of sensitive information tailored to your needs.​

To grant specific users access to view and manage secret scanning alerts, you do this via the Settings tab of the repository. From there, under the "Code security and analysis" section, you can add individuals or teams with roles such as security manager.

The Security tab only displays alerts; access control is handled in Settings.

The best proactive control is push protection. It scans for secrets during a git push and blocks the commit before it enters the repository.

Other options (like CODEOWNERS or security managers) help with oversight but do not prevent secret leaks.

Making a repo public would increase the risk, not reduce it.

Comprehensive and Detailed Explanation:

Push protection for secret scanning custom patterns is an opt-in feature. This means that for each custom pattern defined in a repository, maintainers can choose to enable or disable push protection individually. This provides flexibility, allowing teams to enforce push protection on sensitive patterns while leaving it disabled for others.​

Validity checks — where GitHub verifies if a secret is still active — are available for partner patterns only. These are secrets issued by GitHub's trusted partners (like AWS, Slack, etc.) and have APIs for GitHub to validate token activity status.

Custom patterns and high entropy patterns do not support automated validity checks.

To exclude specific files or directories from being scanned by secret scanning in GitHub Actions, you can use the paths-ignore: key within your YAML workflow file.

This tells GitHub to ignore specified paths when scanning for secrets, which can be useful for excluding test data or non-sensitive mock content.

Other options listed are invalid:

branches-ignore: excludes branches, not files.

decrypt_secret.sh is not a YAML key.

secret scanning.yml is not a recognized filename for configuration.

If autobuild fails (which attempts to automatically detect how to build your project), you should disable it in your workflow and replace it with explicit build commands, using steps like run: make or run: ./gradlew build.

This ensures CodeQL can still extract and analyze the code correctly.

Comprehensive and Detailed Explanation:

When GitHub identifies a vulnerable dependency in a repository with Dependabot alerts enabled, it performs the following actions:​

Generates a Dependabot alert: The alert is displayed on the repository's Security tab, providing details about the vulnerability and affected dependency.​

Notifies repository maintainers: By default, GitHub notifies users with write, maintain, or admin permissions about new Dependabot alerts.​

GitHub Docs

These actions ensure that responsible parties are informed promptly to address the vulnerability.​

A Dependabot alert is only marked as resolved when the related vulnerability is no longer present in your code — specifically after you merge a pull request that updates the vulnerable dependency.

Simply viewing alerts or graphs does not affect their status. Ignoring the alert by leaving the repo unchanged keeps the vulnerability active and unresolved.

When defining a custom pattern for secret scanning, two key fields are required:

Name of the pattern: A unique label to identify the pattern

Secret format: A regular expression that defines what the secret looks like (e.g., token format)

You can optionally specify additional match requirements (like required context keywords), but they’re not mandatory. Listing repositories is also not part of the required fields during pattern creation.

Secret validation checks whether a secret found in your repository is still valid and active with the issuing provider (e.g., AWS, GitHub, Stripe). If a secret is confirmed to be active, the alert is marked as verified, which means it's considered a high-priority issue because it presents an immediate security risk.

This helps teams respond faster to valid, exploitable secrets rather than wasting time on expired or fake tokens.