GH-500 GitHub Advanced Security Exam Questions and Answers

Dependabot builds a dependency graph by analyzing package manifests and lockfiles in your repository. This graph includes both direct and transitive dependencies. It then compares this graph against the GitHub Advisory Database, which includes curated, security-reviewed advisories.

This method provides a comprehensive and automated way to discover all known vulnerabilities across your dependency tree.

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 multiple instances of the same secret value appear in a repository, only one alert is generated. Secret scanning works by identifying exposed credentials and token patterns, and it groups identical matches into a single alert to reduce noise and avoid duplication.

This makes triaging easier and helps teams focus on remediating the actual exposed credential rather than reviewing multiple redundant alerts.

To change the threshold that defines whether a pull request fails due to code scanning alerts (such as blocking merges based on severity), the user must have Admin access on the repository. This is because modifying these settings falls under repository configuration privileges.

Users with Write, Maintain, or Triage roles do not have the required access to modify rulesets or status check policies.

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.​

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.

Comprehensive and Detailed Explanation:

Dependabot alerts are generated based on data from various sources:​

National Vulnerability Database (NVD): A comprehensive repository of known vulnerabilities, which GitHub integrates into its advisory database.​

GitHub Docs

Security Advisories Reported on GitHub: GitHub allows maintainers and security researchers to report and discuss vulnerabilities, which are then included in the advisory database.​

The dependency graph and manifest/lock files are tools used by GitHub to determine which dependencies are present in a repository but are not sources of vulnerability disclosures themselves.​

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.

By default, no repositories receive Dependabot alerts unless configuration is explicitly enabled. GitHub does not enable Dependabot alerts automatically for any repositories unless:

The feature is turned on manually

It's configured at the organization or enterprise level via security policies

This includes public, private, and enterprise-owned repositories — manual activation is required.

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.

By default, users with Write, Maintain, or Admin permissions will receive notifications for new Dependabot alerts. However, Write permission is the minimum level needed to be automatically notified. Users with only Read access do not receive alerts unless added explicitly.

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.

To detect and block vulnerable dependencies before merge, developers should use the Dependency Review GitHub Action in their pull request workflows. It scans all proposed dependency changes and flags any packages with known vulnerabilities.

This is a preventative measure during development, unlike Dependabot, which reacts after the fact.

You must enable secret scanning before defining custom patterns. Secret scanning provides the foundational capability for detecting exposed credentials, and custom patterns build upon that by allowing organizations to specify their own regex-based patterns for secrets unique to their environment.

Without enabling secret scanning, GitHub will not process or apply custom patterns.

When you identify that a code scanning alert is a false positive—such as when your code uses a custom sanitization method not recognized by the analysis—you should dismiss the alert with the reason "false positive." This action helps improve the accuracy of future analyses and maintains the relevance of your security alerts.​

As per GitHub's documentation:​

"If you dismiss a CodeQL alert as a false positive result, for example because the code uses a sanitization library that isn't supported, consider contributing to the CodeQL repository and improving the analysis."​

By dismissing the alert appropriately, you ensure that your codebase's security alerts remain actionable and relevant.

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.

Query suite definitions in CodeQL are stored using the .qls file extension. A query suite defines a collection of queries to be run during an analysis and allows for grouping them based on categories like language, security relevance, or custom filters.

In contrast:

.ql files are individual queries.

.qll files are libraries used by .ql queries.

.yml is used for workflows, not query suites.

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.

Comprehensive and Detailed Explanation:

When configuring Dependabot via the dependabot.yml file, the following fields are mandatory for each update configuration:

directory: Specifies the location of the package manifest within the repository. This tells Dependabot where to look for dependency files.​

package-ecosystem: Indicates the type of package manager (e.g., npm, pip, maven) used in the specified directory.​

schedule.interval: Defines how frequently Dependabot checks for updates (e.g., daily, weekly). This ensures regular scanning for outdated or vulnerable dependencies.​

The milestone field is optional and used for associating pull requests with milestones. The allow field is also optional and used to specify which dependencies to update.​

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