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Mitigation Strategies Analysis for vicc/chameleon

Mitigation Strategy: Verify and Configure Auto-Escaping

Description:

  1. Documentation Review: Thoroughly review the chameleon documentation to understand its auto-escaping mechanisms and configuration options. Identify the specific functions or settings that control escaping.
  2. Enable Auto-Escaping: Ensure that auto-escaping is explicitly enabled in your chameleon configuration. Do not rely on default settings without verifying them.
  3. Context-Specific Escaping: Confirm that chameleon is configured to use the correct escaping mode for the output format (e.g., HTML, XML). Different contexts require different escaping rules.
  4. Testing: Create test cases that deliberately include potentially dangerous characters (e.g., <, >, &, ", ') in template data. Verify that these characters are correctly escaped in the rendered output. Include common XSS payloads in your tests.
  5. Manual Escaping (if needed): If chameleon's auto-escaping is insufficient for a particular context, or if you have any doubts, use chameleon's provided escaping functions explicitly in your code to escape data before passing it to the template. The documentation should detail these functions.
  6. Consider a Wrapper: If you find yourself frequently needing to manually escape, consider creating a wrapper function or class around chameleon's rendering methods to automatically apply the necessary escaping.

  • Threats Mitigated:

    • Cross-Site Scripting (XSS): (Severity: High) - Prevents injection of malicious JavaScript code through template data by ensuring proper escaping.
    • Server-Side Template Injection (SSTI): (Severity: Critical) - While not the primary defense, correct escaping can help mitigate some SSTI attacks that rely on injecting special characters.

  • Impact:

    • XSS: Risk significantly reduced.
    • SSTI: Provides a secondary layer of defense.

  • Currently Implemented:

    • Auto-escaping is believed to be enabled (needs verification).

  • Missing Implementation:

    • Thorough testing with XSS payloads is needed.
    • Documentation of the specific chameleon configuration related to escaping is required.
    • A wrapper function might be beneficial for consistent escaping.

Mitigation Strategy: Review and Configure Chameleon's Error Handling

Description:

  1. Documentation Review: Examine chameleon's documentation for any settings or options related to error reporting, debugging, and exception handling.
  2. Disable Verbose Errors: Identify and disable any settings that might cause chameleon to output detailed error messages, stack traces, or template code snippets in the rendered output. This is crucial for production environments.
  3. Custom Error Handling (Integration): Integrate chameleon's error handling with your application's overall error handling mechanism. Catch any exceptions raised by chameleon during template rendering and handle them gracefully.
  4. Log, Don't Display: Ensure that detailed error information is logged to a secure location (file or logging service) for debugging purposes, but never displayed to the user.

  • Threats Mitigated:

    • Information Disclosure: (Severity: High) - Prevents sensitive information (file paths, template code, internal variables) from being leaked through error messages.

  • Impact:

    • Information Disclosure: Risk significantly reduced.

  • Currently Implemented:

    • General error handling is in place, but chameleon-specific error handling needs review.

  • Missing Implementation:

    • Specific review of chameleon's error handling configuration and integration with the application's error handling is required.

Mitigation Strategy: Restrict Template Language Features (If Possible and Necessary)

Description:

  1. Documentation Review: Examine the chameleon documentation to determine if it offers any mechanisms to restrict the features of the templating language itself. Some templating engines allow you to disable certain features (e.g., dynamic code execution, template inclusion) to reduce the attack surface.
  2. Disable Unnecessary Features: If chameleon provides such options, disable any features that are not strictly required by your application. This limits the potential for attackers to exploit more powerful (and potentially dangerous) features.
  3. Custom Parser/Compiler (Extreme): In very high-security environments, if chameleon doesn't offer sufficient built-in restrictions, you might consider creating a custom parser or compiler for a subset of the chameleon language, enforcing stricter rules. This is a complex and resource-intensive approach.

  • Threats Mitigated:

    • Server-Side Template Injection (SSTI): (Severity: Critical) - Reduces the attack surface by limiting the capabilities of the templating language.
    • Denial of Service (DoS): (Severity: Medium) - Can prevent the use of complex template features that could lead to resource exhaustion.

  • Impact:

    • SSTI: Risk reduced (depending on the restrictions implemented).
    • DoS: Risk potentially reduced.

  • Currently Implemented:

    • Not implemented.

  • Missing Implementation:

    • Requires investigation into chameleon's capabilities and potentially significant development effort.

Mitigation Strategy: Avoid Recursive Includes (If Chameleon Supports Inclusion)

  • Description:

    1. Documentation Review: Check if chameleon supports template inclusion (one template including another).
    2. Avoid Recursion: If inclusion is supported, strictly avoid any recursive inclusion patterns, where a template includes itself (directly or indirectly).
    3. Code Review: During code reviews, specifically check for any potential recursive inclusion scenarios.
    4. Static Analysis (If Possible): If tools are available, use static analysis to detect potential recursive inclusion patterns in your templates.

  • Threats Mitigated:

    • Denial of Service (DoS): (Severity: Medium) - Prevents infinite loops caused by recursive template inclusion, which can lead to resource exhaustion.

  • Impact:

    • DoS: Risk significantly reduced (related to recursive inclusion).

  • Currently Implemented:

    • Not explicitly checked, needs to be verified if chameleon supports inclusion.

  • Missing Implementation:

    • Requires review of template structure and potentially static analysis if inclusion is used.