attack-surface.md

Attack Surface Analysis for pixijs/pixi.js

Attack Surface: Cross-Site Scripting (XSS) via Text Rendering

• Description: Injection of malicious scripts through user-controlled text that is rendered by PixiJS.
• PixiJS Contribution: PixiJS provides functionalities to render text dynamically. If user input is directly used as text content without sanitization, it becomes vulnerable to XSS when rendered by PixiJS.
• Example: An application allows users to input a username which is then displayed on a PixiJS rendered profile card. A malicious user enters <img src=x onerror=alert('XSS')> as their username. PixiJS renders this text, the browser interprets the <img> tag, and executes the JavaScript alert('XSS').
• Impact: Account compromise, session hijacking, redirection to malicious sites, data theft, defacement of the application.
• Risk Severity: High
• Mitigation Strategies:
  • Input Sanitization: Sanitize all user-provided text input before rendering it with PixiJS. Use a robust HTML sanitization library to remove or encode potentially harmful HTML tags and JavaScript.
  • Content Security Policy (CSP): Implement a strict CSP to limit the sources from which scripts can be executed, reducing the impact of successful XSS attacks.

Attack Surface: Malicious Image Files

• Description: Exploiting vulnerabilities in image parsing libraries by loading specially crafted image files from untrusted sources.
• PixiJS Contribution: PixiJS relies on the browser's image loading capabilities to load textures. By loading images from untrusted sources using PixiJS's texture loading mechanisms, the application becomes vulnerable to exploits within image parsing.
• Example: An application allows users to upload images to be used as textures in a PixiJS scene. A malicious user uploads a specially crafted PNG file that exploits a buffer overflow vulnerability in the browser's PNG parsing library. This could lead to browser crash or potentially remote code execution when PixiJS attempts to use this image as a texture.
• Impact: Browser crash, potential remote code execution (depending on the vulnerability), data corruption.
• Risk Severity: High
• Mitigation Strategies:
  • Content Security Policy (CSP): Restrict the sources from which images can be loaded using CSP's img-src directive. Only allow loading images from trusted origins.
  • Input Validation (File Type and Size): Validate the file type and size of uploaded images. While file type validation can be bypassed, it adds a layer of defense. Limit the maximum file size to prevent excessively large files from being processed.
  • Regular Browser Updates: Ensure users are using up-to-date browsers, as browser vendors regularly patch vulnerabilities in image parsing and other components. Encourage users to keep their browsers updated.
  • Server-Side Image Processing (Optional): For uploaded images, consider processing them server-side using robust and updated image processing libraries before serving them to the PixiJS application. This can help sanitize or detect potentially malicious image files.