threat-modeling.md

Threat Model Analysis for swisspol/gcdwebserver

Threat: Path Traversal

• Threat: Path Traversal
• Description: If gcdwebserver's file serving functionality lacks proper input sanitization, an attacker can manipulate HTTP requests to include malicious path components (like ../). By sending requests with these crafted paths, the attacker can bypass intended directory restrictions and access files located outside the designated web server root directory. This allows them to read sensitive files from the server's file system that should not be publicly accessible.
• Impact: Confidentiality breach, unauthorized access to sensitive data including application code, configuration files, and potentially user data stored on the server. This can lead to further system compromise.
• Affected gcdwebserver component: GCDWebServer class, specifically the file serving logic within request handlers and path resolution functions.
• Risk Severity: High
• Mitigation Strategies:
  • Strict Path Validation in Application: The application using gcdwebserver must implement robust validation and sanitization of all file paths received from HTTP requests before passing them to gcdwebserver for file serving. Use functions to normalize paths and verify they remain within the intended base directory.
  • Utilize gcdwebserver Path Restriction Features (if available): Check gcdwebserver documentation for any built-in features to restrict served paths or define allowed directories. If such features exist, configure them strictly.
  • Principle of Least Privilege for File Access: Ensure the application and gcdwebserver process run with minimal file system permissions. Only grant read access to the specific directory intended for web serving and no broader permissions.
  • Code Review: Conduct thorough code reviews of the application's file handling logic and how it interacts with gcdwebserver to ensure path traversal vulnerabilities are not introduced.

Threat: HTTP Request Smuggling/Splitting

• Threat: HTTP Request Smuggling/Splitting
• Description: If gcdwebserver's HTTP request parsing implementation contains vulnerabilities, an attacker can craft malicious HTTP requests that exploit these parsing flaws. By sending ambiguous or malformed requests, the attacker can "smuggle" a second, attacker-controlled request within the same HTTP connection. This can cause the server to misinterpret request boundaries, leading to the second smuggled request being treated as a separate request, potentially bypassing security checks, poisoning caches, or leading to unexpected application behavior.
• Impact: Bypassing security controls implemented in the application or upstream proxies, cache poisoning (if a cache is involved), potential for session hijacking or other attacks depending on how the application processes subsequent requests after smuggling.
• Affected gcdwebserver component: GCDWebServerConnection class, specifically the HTTP request parsing logic within the connection handling.
• Risk Severity: High
• Mitigation Strategies:
  • Keep gcdwebserver Updated: Regularly update to the latest version of gcdwebserver. Security vulnerabilities, including HTTP parsing flaws, are often addressed in updates.
  • Thorough Testing with HTTP Fuzzing: Perform rigorous testing of the application and gcdwebserver using HTTP fuzzing tools. These tools send a wide range of malformed and edge-case HTTP requests to identify potential parsing vulnerabilities.
  • Reverse Proxy/WAF with Request Validation: Deploy a reverse proxy or Web Application Firewall (WAF) in front of the application. A WAF can provide an additional layer of defense by inspecting and validating HTTP requests before they reach gcdwebserver, potentially detecting and blocking smuggling attempts based on protocol deviations.
  • Careful Review of gcdwebserver Source Code (if feasible): If possible and necessary for high-security applications, review the source code of gcdwebserver's HTTP parsing implementation to understand its logic and identify potential vulnerabilities.