Skip to content

Latest commit

 

History

History
49 lines (40 loc) · 7.24 KB

threat-modeling.md

File metadata and controls

49 lines (40 loc) · 7.24 KB

Threat Model Analysis for jgm/pandoc

Threat: Buffer Overflow/Memory Corruption

  • Description: A specially crafted input document, when processed by Pandoc, triggers a buffer overflow or memory corruption vulnerability within Pandoc's parsing logic. This can lead to unpredictable behavior, application crashes, or potentially arbitrary code execution on the server. An attacker could exploit this by providing a malicious document through any input channel the application uses with Pandoc.
  • Impact: Application crash, data corruption, potential for arbitrary code execution, potentially leading to full system compromise.
  • Pandoc Component Affected: Input Parsers (specific parser depends on input format, e.g., docx reader, markdown reader, html reader), potentially core parsing libraries within Pandoc.
  • Risk Severity: Critical.
  • Mitigation Strategies:
    • Pandoc version updates: Immediately update Pandoc to the latest stable version. Security patches for buffer overflows and memory corruption are critical and frequently addressed in updates.
    • Input fuzzing and security testing: If possible, perform fuzzing and security testing of Pandoc with a wide range of input formats to proactively identify potential memory corruption issues. Report any findings to the Pandoc developers.
    • Memory safety practices (if using Pandoc API directly): If your application directly uses the Pandoc API (e.g., Haskell library), ensure you are following memory safety best practices in your own code and when interacting with the Pandoc library.

Threat: Command Injection via External Programs

  • Description: Pandoc utilizes external programs (like LaTeX, PDF engines, or filters) for certain document conversions. If Pandoc fails to properly sanitize input when constructing commands for these external programs, an attacker can inject malicious commands within a crafted input document. When Pandoc executes these commands, the attacker's injected commands are also executed on the server's operating system. This is often achieved by manipulating filenames or options within the input document that are passed to external commands.
  • Impact: Arbitrary code execution on the server, full system compromise, data breach, complete loss of confidentiality, integrity, and availability.
  • Pandoc Component Affected: External Program Execution module within Pandoc, format conversion modules that rely on external tools (e.g., pdf writer, latex writer, filters).
  • Risk Severity: Critical.
  • Mitigation Strategies:
    • Disable external program execution: If your application's functionality does not absolutely require conversions that rely on external programs, configure Pandoc to disable external program execution entirely. This is the most effective mitigation if feasible.
    • Strict input sanitization for external programs: If external programs are necessary, implement extremely rigorous input sanitization and validation before passing any user-controlled data to Pandoc. Assume all user input is potentially malicious. Focus on sanitizing data that might influence command construction for external tools.
    • Principle of Least Privilege: Run the Pandoc process with the absolute minimum privileges required. Use dedicated user accounts with restricted permissions to limit the impact of successful command injection.
    • Sandboxing/Containerization: Consider running Pandoc within a sandboxed environment or container to further isolate it from the host system and limit the damage from potential command injection.

Threat: Malformed Input High Resource Consumption (DoS)

  • Description: A maliciously crafted document is provided as input to Pandoc. This input is designed to exploit inefficiencies or algorithmic complexity in Pandoc's parsing process, causing it to consume excessive CPU, memory, or time. This can lead to a Denial of Service (DoS) condition, making the application unresponsive or unavailable. An attacker could repeatedly submit such documents to overwhelm the server.
  • Impact: Denial of Service, application unavailability, resource exhaustion, impacting legitimate users.
  • Pandoc Component Affected: Input Parsers (specific parser depends on input format, e.g., docx reader, markdown reader, html reader).
  • Risk Severity: High (if easily exploitable and application is critical).
  • Mitigation Strategies:
    • Resource limits: Implement strict resource limits (CPU time, memory usage, processing time) for Pandoc processes. Use operating system level controls or containerization features to enforce these limits.
    • Input validation and complexity analysis: Analyze input documents for excessive complexity or suspicious patterns before processing with Pandoc. Reject or queue overly complex documents for slower processing.
    • Rate limiting: Implement rate limiting on document conversion requests to prevent attackers from overwhelming the system with malicious documents.
    • Pandoc version updates: Keep Pandoc updated, as performance improvements and DoS vulnerability fixes are often included in new releases.

Threat: XML External Entity (XXE) Injection (High Impact File Access)

  • Description: If Pandoc processes XML-based formats (like DOCX, EPUB, or potentially custom XML formats), and XML parsing is not securely configured, an attacker can embed an XML External Entity (XXE) declaration within a crafted input document. This allows the attacker to instruct Pandoc to access external resources, including local files on the server's filesystem. In high-impact scenarios, this can be used to read sensitive configuration files, application code, or other confidential data.
  • Impact: Information disclosure, unauthorized access to sensitive local files, potential for further exploitation if exposed files contain credentials or sensitive data.
  • Pandoc Component Affected: XML Parsers used by Pandoc for XML-based document formats (e.g., DOCX reader, EPUB reader), underlying XML processing libraries.
  • Risk Severity: High (if sensitive files are accessible on the server and exploitable via XXE).
  • Mitigation Strategies:
    • Disable external entity processing: Configure Pandoc and/or the underlying XML processing libraries to completely disable or restrict external entity resolution. This is the most effective mitigation. Consult Pandoc's documentation and the documentation of any XML libraries it uses for configuration options.
    • Input format restriction: If possible, avoid processing XML-based formats if they are not strictly necessary for your application's functionality.
    • Principle of Least Privilege: Run the Pandoc process with minimal necessary file system permissions. This limits the scope of files an attacker could potentially access even if an XXE vulnerability is exploited.
    • Regular Security Audits: Conduct regular security audits and penetration testing, specifically focusing on XML processing and XXE vulnerabilities in the context of Pandoc usage.