threat-modeling.md

Threat Model Analysis for swc-project/swc

Threat: Malicious Code Injection via Compromised swc Package

• Description: An attacker compromises the official swc package (e.g., on npm) or a mirror and injects malicious code. When developers install or update the package, the malicious code is executed during the build process. The attacker could inject code to modify the compiled JavaScript, steal environment variables (API keys, etc.), or compromise the build server itself.
• Impact: Complete compromise of the build process and potentially the resulting application. The attacker could inject arbitrary code into the application, steal sensitive data, or gain control of the build server.
• Affected Component: The entire swc package and its installation process. This affects all modules and functions within swc.
• Risk Severity: Critical
• Mitigation Strategies:
  • Use package lock files (package-lock.json, yarn.lock, pnpm-lock.yaml) to ensure deterministic builds and prevent unexpected updates.
  • Verify package integrity using checksums or subresource integrity (SRI) if available. Some package managers offer built-in integrity checks.
  • Consider using a private package registry (e.g., Verdaccio, Nexus) to host a vetted and controlled copy of swc.
  • Implement Software Composition Analysis (SCA) to detect known vulnerabilities in swc and its dependencies.
  • Regularly monitor security advisories and the swc GitHub repository for reported vulnerabilities.

Threat: Malicious Code Injection via Compromised swc Plugin

• Description: An attacker compromises a third-party swc plugin. When the plugin is used, the malicious code is executed during the build. The attacker's capabilities are limited by the plugin's functionality, but they could still modify the compiled code or access build-time information.
• Impact: Depends on the plugin's role. Could range from minor code modifications to significant vulnerabilities, including code injection or data exfiltration.
• Affected Component: The specific compromised swc plugin and any swc core functionality it interacts with.
• Risk Severity: High to Critical (depending on the plugin)
• Mitigation Strategies:
  • Thoroughly vet any third-party swc plugins before use. Consider the author's reputation, community support, and update frequency.
  • Use package lock files to pin plugin versions.
  • Regularly audit the code of third-party plugins, if feasible.
  • Use SCA tools to identify known vulnerabilities in plugins.
  • Limit the use of plugins to those that are absolutely necessary.

Threat: Code Transformation Bug Leading to XSS

• Description: A bug in swc's transpilation logic, specifically related to handling user input or string interpolation, incorrectly transforms code, creating a Cross-Site Scripting (XSS) vulnerability in the output JavaScript that was not present in the source code. An attacker could exploit this to inject malicious scripts into the application.
• Impact: Allows an attacker to execute arbitrary JavaScript in the context of a user's browser, potentially stealing cookies, session tokens, or redirecting the user to a malicious site.
• Affected Component: swc's core transpilation engine, specifically modules related to parsing, transforming, and generating JavaScript code (e.g., the parser, the transformer, and the emitter). The specific functions involved would depend on the nature of the bug.
• Risk Severity: High
• Mitigation Strategies:
  • Thoroughly test the compiled application for XSS vulnerabilities, using both automated tools and manual penetration testing. Focus on areas where user input is handled.
  • Regularly update to the latest swc version to benefit from bug fixes.
  • Report any suspected transpilation bugs to the swc developers.
  • Use a Content Security Policy (CSP) to mitigate the impact of XSS vulnerabilities.
  • If possible, use a framework that automatically escapes user input (e.g., React, Vue, Angular) to reduce the likelihood of swc bugs introducing XSS.

Threat: Minification Bug Removing Security Checks

• Description: swc's minifier, due to a bug or overly aggressive optimization, removes code that it incorrectly identifies as dead code, but which is actually a crucial security check (e.g., an authorization check, input validation).
• Impact: Bypass of security controls, potentially allowing unauthorized access to data or functionality.
• Affected Component: swc's minifier module (e.g., swc_ecma_minifier).
• Risk Severity: High
• Mitigation Strategies:
  • Carefully review the minification options used. Avoid overly aggressive settings unless absolutely necessary. Test different optimization levels.
  • Thoroughly test the minified application, paying close attention to security-related functionality.
  • Use code comments or directives (if supported by swc) to prevent the minifier from removing specific code blocks.
  • Consider using a less aggressive minifier or disabling minification for critical code sections.