mitigations.md

Mitigation Strategies Analysis for evanw/esbuild

Mitigation Strategy: Regularly Update esbuild

• Description:
  • Step 1: Monitor esbuild releases on the official GitHub repository (https://github.com/evanw/esbuild/releases) or npm (https://www.npmjs.com/package/esbuild).
  • Step 2: Subscribe to security mailing lists or vulnerability databases that might report issues related to esbuild or JavaScript build tools in general.
  • Step 3: Regularly check your project's package.json or equivalent dependency file for the currently used esbuild version.
  • Step 4: If a new stable version of esbuild is available, update the version in your package.json file.
  • Step 5: Run your package manager's update command (e.g., npm update esbuild, yarn upgrade esbuild) to fetch and install the latest version.
  • Step 6: Thoroughly test your application after updating esbuild to ensure compatibility and no regressions are introduced, focusing on build process and performance.
• Threats Mitigated:
  • Known Vulnerabilities in esbuild: Exploitation of publicly disclosed security flaws in older versions of esbuild. (Severity: High to Critical, depending on the vulnerability)
  • Zero-day Vulnerabilities: While updates don't directly prevent zero-days, they ensure faster patching when vulnerabilities are discovered and fixed by the esbuild team. (Severity: High to Critical, depending on the vulnerability, mitigated indirectly)
• Impact:
  • Known Vulnerabilities in esbuild: High Reduction - Directly addresses and eliminates known vulnerabilities fixed in newer versions.
  • Zero-day Vulnerabilities: Medium Reduction - Reduces the window of exposure to newly discovered vulnerabilities by enabling quicker patching.
• Currently Implemented: Yes, in package.json and CI/CD pipeline. We have a monthly dependency update schedule.
• Missing Implementation: Automated notifications for new esbuild releases are not yet implemented. We rely on manual checks during monthly updates.

Mitigation Strategy: Use Dependency Check Tools

• Description:
  • Step 1: Integrate a dependency scanning tool into your development workflow and CI/CD pipeline. Examples include npm audit, yarn audit, Snyk, or OWASP Dependency-Check.
  • Step 2: Configure the tool to scan your package.json and lock files (e.g., package-lock.json, yarn.lock) for vulnerabilities in all dependencies, including esbuild and its transitive dependencies.
  • Step 3: Run the dependency check tool regularly, ideally on every commit or pull request, and certainly as part of the CI/CD build process.
  • Step 4: Review the tool's output for reported vulnerabilities. Prioritize vulnerabilities affecting esbuild or its direct dependencies.
  • Step 5: If vulnerabilities are found, investigate them. Determine if they are relevant to your application's usage of esbuild.
  • Step 6: If a vulnerability is confirmed and relevant, update esbuild or its vulnerable dependency to a patched version, if available. If no patch is available, consider workarounds or alternative solutions.
  • Step 7: Configure the CI/CD pipeline to fail builds if high-severity vulnerabilities are detected in esbuild or its dependencies, preventing vulnerable code from being deployed.
• Threats Mitigated:
  • Known Vulnerabilities in esbuild and Dependencies: Exploitation of known security flaws in esbuild itself or any of its dependencies (direct or transitive). (Severity: High to Critical, depending on the vulnerability)
  • Supply Chain Attacks: Detection of compromised dependencies that might be introduced through the dependency tree of esbuild. (Severity: Medium to High, depending on the nature of the compromise)
• Impact:
  • Known Vulnerabilities in esbuild and Dependencies: High Reduction - Proactively identifies and alerts developers to known vulnerabilities, enabling timely remediation.
  • Supply Chain Attacks: Medium Reduction - Can detect known vulnerabilities in compromised packages, but might not detect sophisticated, novel supply chain attacks.
• Currently Implemented: Yes, npm audit is integrated into our CI/CD pipeline and runs on every build. Snyk is used for more in-depth scanning on a weekly basis.
• Missing Implementation: Automated vulnerability remediation (e.g., automatic pull requests to update vulnerable dependencies) is not fully implemented. Remediation is currently a manual process.

Mitigation Strategy: Pin esbuild Version in Package Manager

• Description:
  • Step 1: Open your project's package.json file.
  • Step 2: Locate the esbuild dependency entry in the dependencies or devDependencies section.
  • Step 3: Ensure the version specified for esbuild is an exact version number (e.g., "esbuild": "0.17.17") instead of a version range (e.g., "esbuild": "^0.17.0" or "esbuild": "~0.17.0").
  • Step 4: If using yarn, ensure your yarn.lock file is committed to version control. If using npm, ensure your package-lock.json file is committed. These lock files ensure consistent dependency versions across environments.
  • Step 5: When updating esbuild, explicitly change the version number in package.json and run your package manager's install command to update the lock file.
• Threats Mitigated:
  • Unexpected esbuild Updates: Prevents automatic, potentially breaking or vulnerability-introducing updates of esbuild due to version ranges in package.json. (Severity: Low to Medium, depending on the nature of the unexpected update)
  • Inconsistent Builds: Ensures consistent esbuild versions across development, staging, and production environments, reducing the risk of environment-specific issues or vulnerabilities related to build process. (Severity: Low to Medium, depending on inconsistencies)
• Impact:
  • Unexpected esbuild Updates: Medium Reduction - Eliminates the risk of automatic minor or patch updates introducing unforeseen issues.
  • Inconsistent Builds: High Reduction - Significantly reduces the risk of version inconsistencies across environments for esbuild.
• Currently Implemented: Yes, we use exact version pinning for esbuild and all critical dependencies in package.json and commit lock files.
• Missing Implementation: No missing implementation for version pinning itself. However, the process of updating pinned versions could be more streamlined (e.g., using scripts to update version in package.json and lock files simultaneously).

Mitigation Strategy: Verify esbuild Installation Integrity

• Description:
  • Step 1: After installing esbuild via npm or yarn, obtain the expected SHA checksum for the installed esbuild package. This checksum can be found in the npm-shrinkwrap.json (for npm) or yarn.lock (for yarn) file, or potentially from the official esbuild release notes or repository.
  • Step 2: Calculate the SHA checksum of the installed esbuild package on your system. The exact method depends on your OS and package manager. For npm, you might inspect the contents of node_modules/esbuild and calculate the checksum of the main esbuild binary. For yarn, you can inspect the yarn cache.
  • Step 3: Compare the calculated checksum with the expected checksum.
  • Step 4: If the checksums match, the integrity of the esbuild installation is verified. If they don't match, it indicates potential tampering or corruption during download or installation. Reinstall esbuild and re-verify.
  • Step 5: For automated verification, integrate checksum verification into your build scripts or CI/CD pipeline. This can be done using scripting languages and checksum utilities (like sha256sum on Linux/macOS or Get-FileHash on PowerShell).
• Threats Mitigated:
  • Compromised esbuild Package: Mitigates the risk of using a tampered or malicious esbuild package downloaded from npm or a compromised registry. (Severity: High to Critical, depending on the nature of the compromise)
  • Man-in-the-Middle Attacks during Download: Reduces the risk of a MITM attack during package download that could replace the legitimate esbuild package with a malicious one. (Severity: Medium to High, depending on the attack scenario)
• Impact:
  • Compromised esbuild Package: High Reduction - Provides a strong mechanism to detect and prevent the use of compromised packages.
  • Man-in-the-Middle Attacks during Download: Medium Reduction - Reduces the risk, but relies on secure distribution of checksum information.
• Currently Implemented: No, checksum verification of esbuild installation is not currently implemented. We rely on the security of npm/yarn and HTTPS for package downloads.
• Missing Implementation: Checksum verification should be added to our CI/CD pipeline and potentially as a pre-build step in local development environments. We need to determine the best way to reliably obtain and verify esbuild checksums.

Mitigation Strategy: Carefully Vet and Select Plugins

• Description:
  • Step 1: Before using any esbuild plugin, thoroughly research and evaluate it.
  • Step 2: Check the plugin's source code repository (e.g., GitHub, GitLab) for activity, maintainership, and community engagement. Look for recent commits, issue resolution, and a healthy number of contributors.
  • Step 3: Review the plugin's documentation and examples to understand its functionality and how it interacts with your esbuild build process.
  • Step 4: Check the plugin's npm page for download statistics, version history, and any reported vulnerabilities or security concerns.
  • Step 5: Prioritize plugins from reputable authors or organizations with a proven track record in the JavaScript ecosystem.
  • Step 6: Be wary of plugins with very low download counts, no recent updates, or unclear origins. Consider alternatives if available.
  • Step 7: If possible, test the plugin in a non-production environment before deploying it to production builds.
• Threats Mitigated:
  • Malicious Plugins: Prevents the introduction of intentionally malicious esbuild plugins that could compromise the build process, inject malicious code into build outputs, or steal sensitive information. (Severity: High to Critical, depending on the plugin's capabilities)
  • Vulnerable Plugins: Avoids using esbuild plugins with known security vulnerabilities that could be exploited during the build process or in the built application. (Severity: Medium to High, depending on the vulnerability)
  • Poorly Maintained Plugins: Reduces the risk of using esbuild plugins that are no longer maintained and might contain unfixed vulnerabilities or compatibility issues. (Severity: Low to Medium, related to long-term security and stability)
• Impact:
  • Malicious Plugins: High Reduction - Significantly reduces the risk of introducing malicious code through esbuild plugins.
  • Vulnerable Plugins: Medium Reduction - Helps avoid known vulnerable esbuild plugins, but relies on available vulnerability information.
  • Poorly Maintained Plugins: Medium Reduction - Improves long-term security and stability by favoring actively maintained esbuild plugins.
• Currently Implemented: Partially implemented. We have a general guideline to vet plugins, but it's not a formal, documented process. Plugin selection is often based on functionality and popularity, with less emphasis on in-depth security vetting.
• Missing Implementation: We need to formalize the esbuild plugin vetting process. This should include a documented checklist for evaluating plugins, security review guidelines, and potentially a list of approved/disapproved plugins.

Mitigation Strategy: Review Plugin Code and Dependencies

• Description:
  • Step 1: For esbuild plugins that perform complex operations or interact with external resources, and especially for plugins from less well-known sources, review their source code.
  • Step 2: Focus on understanding how the plugin manipulates code, handles user inputs, interacts with the file system, and makes network requests within the context of esbuild build process.
  • Step 3: Look for potential security vulnerabilities in the plugin's code, such as code injection vulnerabilities, path traversal issues, insecure data handling, or reliance on insecure dependencies.
  • Step 4: Analyze the plugin's dependencies (listed in its package.json or equivalent). Use dependency check tools (as described earlier) to scan the plugin's dependencies for known vulnerabilities.
  • Step 5: If you find security concerns or vulnerabilities, consider alternatives to the plugin, contribute fixes to the plugin if possible, or avoid using the plugin altogether.
• Threats Mitigated:
  • Vulnerabilities in Plugin Code: Detects and prevents the use of esbuild plugins with security vulnerabilities in their own code that might not be caught by dependency scanners. (Severity: Medium to High, depending on the vulnerability)
  • Vulnerabilities in Plugin Dependencies: Identifies vulnerabilities in the dependencies of esbuild plugins that might be missed by top-level dependency scans if not properly transitive. (Severity: Medium to High, depending on the vulnerability)
  • Backdoors or Malicious Logic in Plugin Code: While harder to detect, code review can sometimes reveal suspicious or malicious logic in esbuild plugin code that might not be obvious from plugin descriptions or documentation. (Severity: High to Critical, if malicious logic is present)
• Impact:
  • Vulnerabilities in Plugin Code: Medium Reduction - Can identify vulnerabilities missed by automated tools, but requires manual code review expertise.
  • Vulnerabilities in Plugin Dependencies: Medium Reduction - Provides a more thorough dependency vulnerability analysis for esbuild plugins.
  • Backdoors or Malicious Logic in Plugin Code: Low to Medium Reduction - Code review can help, but detecting sophisticated backdoors is challenging.
• Currently Implemented: No, we do not currently perform routine code reviews of esbuild plugins. Plugin selection is primarily based on functionality and general reputation.
• Missing Implementation: We should implement a process for code review of esbuild plugins, especially for new plugins or plugins used in critical parts of the build process. This could be risk-based, focusing on plugins with higher complexity or broader access.

Mitigation Strategy: Use Plugin Checksums/Integrity Verification

• Description:
  • Step 1: If esbuild plugin authors provide checksums (e.g., SHA hashes) for their plugin packages, obtain these checksums from a trusted source (e.g., the plugin's official website, repository, or release notes).
  • Step 2: After installing a plugin, calculate the checksum of the installed plugin package.
  • Step 3: Compare the calculated checksum with the provided checksum.
  • Step 4: If the checksums match, the integrity of the esbuild plugin installation is verified. If they don't match, it indicates potential tampering or corruption. Reinstall the plugin and re-verify.
  • Step 5: For automated verification, integrate checksum verification into your build scripts or plugin management process for esbuild plugins.
• Threats Mitigated:
  • Compromised Plugin Packages: Mitigates the risk of using tampered or malicious esbuild plugin packages downloaded from npm or a compromised registry. (Severity: High to Critical, depending on the nature of the compromise)
  • Man-in-the-Middle Attacks during Plugin Download: Reduces the risk of MITM attacks during esbuild plugin download that could replace legitimate plugins with malicious ones. (Severity: Medium to High, depending on the attack scenario)
• Impact:
  • Compromised Plugin Packages: High Reduction - Provides a strong mechanism to detect and prevent the use of compromised esbuild plugin packages, if checksums are available and reliably distributed.
  • Man-in-the-Middle Attacks during Plugin Download: Medium Reduction - Reduces the risk, but relies on secure distribution of checksum information by plugin authors.
• Currently Implemented: No, esbuild plugin checksum verification is not currently implemented. We rely on the security of npm/yarn and HTTPS for plugin downloads. Plugin authors rarely provide checksums.
• Missing Implementation: We should explore options for esbuild plugin checksum verification. This might involve encouraging plugin authors to provide checksums and developing tooling to automate the verification process. If checksums are not readily available, we might need to explore alternative integrity verification methods.

Mitigation Strategy: Secure esbuild Configuration

• Description:
  • Step 1: Review your esbuild configuration files (e.g., esbuild.config.js, command-line arguments) and build scripts that use esbuild.
  • Step 2: Ensure that esbuild configuration options are set securely. Avoid overly permissive settings that could introduce vulnerabilities.
  • Step 3: Specifically, check for:
    • File System Access: Limit esbuild's access to only necessary files and directories. Avoid using wildcard patterns that could expose sensitive files during build.
    • External Resources: If esbuild configuration involves fetching external resources, ensure these are from trusted sources and use HTTPS.
    • Sensitive Information: Avoid hardcoding sensitive information (API keys, secrets) directly in esbuild configuration files or build scripts. Use environment variables or secure secret management solutions instead.
    • Output Paths: Ensure esbuild build output paths are properly configured to prevent accidental overwriting of important files or directories outside the intended build output area.
  • Step 4: Regularly audit your esbuild configuration as your application evolves to ensure it remains secure.
• Threats Mitigated:
  • Information Disclosure via esbuild Configuration: Insecure configuration could unintentionally expose sensitive files or information in build outputs or logs generated by esbuild. (Severity: Medium to High, depending on the sensitivity of exposed information)
  • Unauthorized File System Access via esbuild Configuration: Overly permissive file system access in esbuild configuration could be exploited to read or write arbitrary files on the build system during esbuild execution. (Severity: High, if write access is granted)
  • Supply Chain Attacks via External Resources in esbuild Configuration: Fetching external resources from untrusted sources in esbuild configuration could introduce malicious code or dependencies into the build process. (Severity: Medium to High, depending on the nature of the external resource)
  • Exposure of Secrets in esbuild Configuration: Hardcoding secrets in esbuild configuration files makes them vulnerable to accidental exposure in version control or logs. (Severity: High, if secrets are compromised)
• Impact:
  • Information Disclosure via esbuild Configuration: Medium Reduction - Prevents unintentional exposure of sensitive information through esbuild configuration flaws.
  • Unauthorized File System Access via esbuild Configuration: High Reduction - Significantly reduces the risk of unauthorized file system operations by esbuild.
  • Supply Chain Attacks via External Resources in esbuild Configuration: Medium Reduction - Mitigates risks associated with untrusted external resources used by esbuild.
  • Exposure of Secrets in esbuild Configuration: High Reduction - Eliminates hardcoded secrets in esbuild configuration.
• Currently Implemented: Partially implemented. We generally avoid hardcoding secrets and use environment variables. File system access in esbuild configuration is reviewed, but not systematically audited.
• Missing Implementation: We need to establish a formal security review process for esbuild configuration and build scripts. This should include documented guidelines for secure configuration and regular audits to ensure compliance.

Mitigation Strategy: Code Review Build Scripts

• Description:
  • Step 1: Implement mandatory code reviews for all changes to build scripts that use esbuild or interact with the esbuild build process.
  • Step 2: Train developers on secure coding practices for build scripts, including input validation, output sanitization, secure file handling, and avoiding command injection vulnerabilities, specifically in the context of using esbuild.
  • Step 3: During code reviews, specifically look for:
    • Command Injection: Ensure user inputs or external data are not directly incorporated into shell commands executed by build scripts when interacting with esbuild or related tools. Use parameterized commands or safe APIs instead.
    • Path Traversal: Verify that file paths used in build scripts when configuring or invoking esbuild are properly validated and sanitized to prevent path traversal vulnerabilities.
    • Insecure File Handling: Check for insecure file operations performed by build scripts in relation to esbuild's input or output files, such as creating files with world-writable permissions or reading/writing sensitive files without proper authorization.
    • Dependency Management: Review changes to build script dependencies to ensure no new vulnerable or malicious dependencies are introduced that could affect the esbuild build process.
    • Error Handling: Ensure build scripts handle errors gracefully and don't leak sensitive information in error messages or logs related to esbuild execution.
  • Step 4: Use static analysis tools to automatically scan build scripts for potential security vulnerabilities related to esbuild usage.
• Threats Mitigated:
  • Command Injection in Build Scripts using esbuild: Prevents command injection vulnerabilities in build scripts that could allow attackers to execute arbitrary commands on the build server when interacting with esbuild. (Severity: High to Critical, depending on the permissions of the build process)
  • Path Traversal in Build Scripts using esbuild: Mitigates path traversal vulnerabilities that could allow attackers to access or manipulate files outside the intended build directory through build scripts interacting with esbuild.
  • Insecure File Operations in Build Scripts related to esbuild: Prevents insecure file handling practices that could lead to information disclosure or unauthorized file modification in the context of esbuild build process. (Severity: Medium to High, depending on the nature of insecure operations)
  • Introduction of Vulnerable Dependencies in Build Scripts affecting esbuild: Reduces the risk of introducing vulnerabilities through dependencies used by build scripts themselves that could compromise the esbuild build. (Severity: Medium to High, depending on the vulnerability)
• Impact:
  • Command Injection in Build Scripts using esbuild: High Reduction - Code review is a crucial defense against command injection in build scripts interacting with esbuild.
  • Path Traversal in Build Scripts using esbuild: Medium Reduction - Code review can effectively identify path traversal issues in build scripts configuring esbuild.
  • Insecure File Operations in Build Scripts related to esbuild: Medium Reduction - Code review helps enforce secure file handling practices in build scripts managing esbuild's files.
  • Introduction of Vulnerable Dependencies in Build Scripts affecting esbuild: Medium Reduction - Code review can catch dependency-related issues, especially when combined with dependency scanning.
• Currently Implemented: Yes, we have mandatory code reviews for all code changes, including build scripts. Security aspects are considered during code reviews, but specific security checklists for build scripts related to esbuild are not yet formalized.
• Missing Implementation: We need to develop and implement a specific security checklist for code reviews of build scripts, focusing on secure usage of esbuild. This checklist should cover common build script vulnerabilities and secure coding practices relevant to esbuild. Static analysis tools for build scripts could also be integrated.

Mitigation Strategy: Static Analysis of Build Configuration

• Description:
  • Step 1: Integrate static analysis tools into your development workflow and CI/CD pipeline to automatically scan esbuild configuration files and build scripts.
  • Step 2: Configure the static analysis tools to detect potential security misconfigurations, vulnerabilities, and insecure coding practices in build-related files, specifically those related to esbuild.
  • Step 3: Examples of static analysis checks for esbuild build configurations include:
    • Detection of hardcoded secrets in esbuild configuration.
    • Identification of overly permissive file system access patterns in esbuild configuration.
    • Analysis of external resource URLs used in esbuild configuration for security risks.
    • Detection of potential command injection vulnerabilities in build scripts that invoke esbuild (some tools can detect basic cases).
    • Linting for insecure coding practices in JavaScript build scripts that configure or use esbuild.
  • Step 4: Run static analysis regularly, ideally on every commit or pull request, and as part of the CI/CD build process.
  • Step 5: Review the static analysis reports and address identified issues related to esbuild. Prioritize security-related findings.
  • Step 6: Configure the CI/CD pipeline to fail builds if critical security issues related to esbuild are detected by static analysis.
• Threats Mitigated:
  • Insecure esbuild Configuration: Detects and prevents insecure esbuild configurations that could lead to information disclosure, unauthorized access, or other vulnerabilities. (Severity: Medium to High, depending on the misconfiguration)
  • Vulnerabilities in Build Scripts using esbuild: Identifies potential vulnerabilities in build scripts that use esbuild, such as command injection or path traversal, that can be detected through static analysis. (Severity: Medium to High, depending on the vulnerability)
  • Hardcoded Secrets in esbuild Configuration: Detects accidental inclusion of secrets in esbuild configuration files or build scripts. (Severity: High, if secrets are exposed)
• Impact:
  • Insecure esbuild Configuration: Medium Reduction - Automates the detection of common esbuild configuration security issues.
  • Vulnerabilities in Build Scripts using esbuild: Medium Reduction - Can identify certain types of vulnerabilities in build scripts using esbuild, complementing code review.
  • Hardcoded Secrets in esbuild Configuration: High Reduction - Effectively detects hardcoded secrets in scanned esbuild configuration files.
• Currently Implemented: No, we do not currently use dedicated static analysis tools specifically for esbuild configuration or build scripts. We rely on general code linters and manual code reviews.
• Missing Implementation: We should evaluate and integrate static analysis tools that are suitable for scanning JavaScript build scripts and configuration files, specifically looking for security issues related to esbuild usage. Tools that can detect security-specific issues in build contexts involving esbuild would be particularly valuable.

Mitigation Strategy: Code Review of Critical Generated Code (If Applicable)

• Description:
  • Step 1: For critical parts of your application or when using advanced esbuild features or custom plugins that significantly transform code, consider reviewing the generated JavaScript code output by esbuild.
  • Step 2: Focus on reviewing the generated code for security-sensitive areas, such as authentication, authorization, data handling, and user input processing, ensuring that esbuild's transformations haven't introduced issues.
  • Step 3: Look for unexpected code patterns, potential vulnerabilities introduced during esbuild code transformation, or deviations from the original source code that might have security implications due to esbuild.
  • Step 4: This is a more in-depth and time-consuming mitigation, so prioritize it for critical applications or when there are specific concerns about the code generation process of esbuild or its plugins.
• Threats Mitigated:
  • Vulnerabilities Introduced by esbuild Code Generation: Detects vulnerabilities that might be unintentionally introduced by esbuild's code generation or plugin transformations, especially in complex scenarios. (Severity: Medium to High, depending on the vulnerability and complexity of transformations)
  • Unexpected Code Behavior from esbuild Output: Identifies unexpected or unintended code behavior in the generated output of esbuild that might have security implications, even if not directly a vulnerability. (Severity: Low to Medium, depending on the behavior)
• Impact:
  • Vulnerabilities Introduced by esbuild Code Generation: Medium Reduction - Can identify subtle vulnerabilities introduced during esbuild code transformation, but requires manual code review expertise and is resource-intensive.
  • Unexpected Code Behavior from esbuild Output: Medium Reduction - Helps ensure the generated code by esbuild behaves as expected from a security perspective.
• Currently Implemented: No, we do not currently perform routine code reviews of generated esbuild output. We rely on security testing of the built application and code reviews of source code and build scripts.
• Missing Implementation: Code review of generated code by esbuild could be considered for highly critical applications or when using complex esbuild configurations or plugins. We need to assess the cost-benefit and determine if this level of review is necessary for specific projects or components.