mitigations.md

Mitigation Strategies Analysis for juliangruber/isarray

Mitigation Strategy: Replace isarray with Defensively Copied Array.isArray

Description:

1. Capture Original Function: At the very beginning of your application's main entry point (e.g., index.js, app.js), before any other code, capture the original Array.isArray function:

   const originalIsArray = Array.isArray;

2. Remove isarray Dependency: Remove the isarray package from your project's dependencies. This is a crucial step to eliminate any potential (however small) risk from the package itself. Use your package manager (e.g., npm uninstall isarray or yarn remove isarray).
3. Replace All Usages: Systematically replace every instance of isarray(...) in your codebase with originalIsArray(...). This ensures that you are using the protected, original implementation.
4. Thorough Testing: Run your complete test suite to verify that all array checks are functioning correctly after the replacement and that no regressions have been introduced.

• List of Threats Mitigated:

  • Threat: Vulnerabilities within the isarray package itself (extremely unlikely, but theoretically possible).
    • Severity: Very Low. isarray is extremely simple, but removing it eliminates this risk entirely.
  • Threat: Supply Chain Attacks targeting isarray.
    • Severity: Very Low. While unlikely, removing the dependency eliminates the risk of a compromised version of isarray being introduced.
  • Threat: Prototype Pollution or Overriding of Array.isArray affecting isarray's behavior.
    • Severity: High (in the context of this specific vulnerability). By using the defensively copied originalIsArray, you ensure that even if the global Array.isArray is compromised, your array checks remain reliable.

• Impact:

  • isarray Vulnerabilities: Risk is eliminated (by removing the dependency).
  • Supply Chain Attacks: Risk is eliminated (by removing the dependency).
  • Prototype Pollution/Overriding: Risk is significantly reduced. The application uses the original, untainted function.

• Currently Implemented:

  • Examples (adapt to your project):
    • "Yes, fully implemented. isarray has been removed, and all uses have been replaced with originalIsArray."
    • "Partially implemented. isarray has been removed, but some files still use Array.isArray directly (without the defensive copy)."
    • "No, not currently implemented. isarray is still a dependency and is used directly."

• Missing Implementation:

  • Examples (adapt to your project):
    • "Missing implementation. isarray is still a dependency and is used throughout the codebase."
    • "Partially missing. isarray has been removed, but the defensive copying strategy is not consistently applied (some files use Array.isArray directly)."
    • "Fully implemented; no missing implementation." This single, focused strategy directly addresses the use of isarray by removing it and replacing it with a protected, built-in alternative. This is the most effective way to mitigate any potential risks associated with the package itself, while also addressing the broader concern of prototype pollution.