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Attack Surface Analysis for fabiomsr/drawable-optimizer

Attack Surface: Malformed Image Exploitation (Parsing Vulnerabilities)

  • 1. Malformed Image Exploitation (Parsing Vulnerabilities)

    • Description: Attackers craft malicious image files (PNG, JPG, WebP, SVG, XML) designed to exploit vulnerabilities in image parsing libraries or drawable-optimizer's own processing logic. This is the primary attack vector.
    • drawable-optimizer Contribution: The library's core function is to parse and process image data, making it the direct target. It acts as the gateway for exploiting vulnerabilities in underlying parsing libraries. Its own internal logic for handling parsed data is also a potential target.
    • Example:
      • PNG: A crafted PNG with a malicious iCCP chunk triggers a buffer overflow in the underlying parsing library (e.g., libpng).
      • SVG/XML: An SVG containing a malicious <script> tag (leading to XSS) or an XXE payload (to access local files or internal network resources) is processed by drawable-optimizer without proper sanitization.
      • WebP: A crafted WebP file exploits a vulnerability in the libwebp decoder.
    • Impact: Arbitrary Code Execution (ACE), Cross-Site Scripting (XSS) (specifically for SVG/XML if output is used in a web context), Information Disclosure, Denial of Service (DoS).
    • Risk Severity: Critical (for ACE, XSS), High (for Information Disclosure, DoS).
    • Mitigation Strategies:
      • Input Validation:
        • Strict Format Validation: Before any parsing, rigorously validate that the input conforms to the expected image format specification. Use magic numbers and header checks, not just file extensions.
        • Size/Dimension Limits: Enforce strict limits on file size and image dimensions (width, height).
      • Dependency Management:
        • Regular Audits: Use dependency vulnerability scanners (e.g., npm audit, yarn audit, OWASP Dependency-Check).
        • Prompt Updates: Keep all dependencies, especially image parsing libraries, updated to their latest secure versions.
      • SVG/XML-Specific (Critical):
        • XXE Prevention: Disable DTD processing and external entity resolution in the XML parser used for SVG and XML Vector Drawables. Use a parser configuration that explicitly disallows these.
        • SVG Sanitization: Implement robust SVG sanitization to remove all potentially dangerous elements and attributes. Use a dedicated, well-vetted SVG sanitization library (e.g., DOMPurify if the output is ever used in a web context). A whitelist approach is essential.
      • Fuzz Testing: Regularly fuzz test drawable-optimizer with a wide range of malformed and edge-case image inputs.
      • Least Privilege: Run application with minimal necessary privileges.

Attack Surface: Command Injection

  • 2. Command Injection

    • Description: If drawable-optimizer uses external tools via command line, improper input sanitization can lead to command injection vulnerabilities.
    • drawable-optimizer Contribution: The library might shell out to external tools (e.g., optipng, jpegoptim, svgo) to perform specific optimization tasks. This is a direct contribution to the attack surface.
    • Example: drawable-optimizer takes a filename as input and directly uses it in a shell command without proper escaping. An attacker provides a filename like "; rm -rf /; #.png" to execute arbitrary commands.
    • Impact: Arbitrary Code Execution (ACE), System Compromise.
    • Risk Severity: Critical.
    • Mitigation Strategies:
      • Avoid Shell Execution: Prefer direct API calls to external tools instead of shelling out. Many image optimization tools have libraries that can be used directly.
      • Input Sanitization: If shell execution is unavoidable, rigorously sanitize and escape any user-provided input in the command string. Use appropriate escaping functions for the target shell. A whitelist approach is strongly recommended.
      • Parameterization: Use parameterized commands or APIs that separate the command from the data.
      • Least Privilege: Run external tools with minimal necessary privileges.