attack-surface.md

Attack Surface Analysis for boostorg/boost

Attack Surface: Buffer Overflow in String/Data Handling

• Description: Writing beyond the allocated memory buffer, leading to potential crashes, memory corruption, or code execution.
• Boost Contribution: Boost libraries like Boost.Asio, Boost.Regex, Boost.Format, and others that handle string manipulation, data parsing, or serialization might contain vulnerabilities or be misused in ways that lead to buffer overflows. Specifically, incorrect usage of buffer management in Boost.Asio or vulnerabilities within parsing logic of Boost.Regex or Boost.Serialization could directly cause overflows.
• Example: Using Boost.Asio to receive network data into a fixed-size buffer without proper size validation, allowing an attacker to send more data than the buffer can hold, overwriting adjacent memory. Another example is a vulnerability in Boost.Regex's handling of certain regex patterns leading to an internal buffer overflow during processing.
• Impact: Code execution, denial of service, information disclosure, data corruption.
• Risk Severity: Critical to High
• Mitigation Strategies:
  • Use Bounds-Checked APIs: Favor Boost APIs and C++ standard library functions that perform bounds checking when handling data.
  • Validate Input Sizes: Always validate the size of input data before processing it with Boost libraries, especially network inputs or data from untrusted sources.
  • Use Dynamic Buffers: When possible, use dynamic buffers (e.g., std::vector, std::string, Boost.Asio dynamic buffers) to avoid fixed-size buffer limitations.
  • Code Reviews and Static Analysis: Conduct thorough code reviews and use static analysis tools to identify potential buffer overflow vulnerabilities, specifically focusing on Boost library usage.
  • Regularly Update Boost: Keep Boost libraries updated to the latest stable versions to benefit from bug fixes and security patches that may address buffer overflow vulnerabilities.

Attack Surface: Deserialization Vulnerabilities (Object Injection, Data Corruption)

• Description: Exploiting vulnerabilities in deserialization processes to inject malicious objects, corrupt data, or execute arbitrary code.
• Boost Contribution: Boost.Serialization provides powerful serialization capabilities, but deserializing untrusted data without careful consideration can introduce significant security risks. The library's design, while flexible, can be misused to allow object injection if not handled securely.
• Example: An application uses Boost.Serialization to deserialize data received from a network connection. An attacker crafts malicious serialized data that, when deserialized, instantiates a harmful object (object injection) or overwrites critical application data.
• Impact: Code execution, data corruption, denial of service, privilege escalation.
• Risk Severity: High to Critical
• Mitigation Strategies:
  • Avoid Deserializing Untrusted Data: If possible, avoid deserializing data from untrusted sources entirely. Consider alternative data exchange formats if security is paramount.
  • Input Validation and Sanitization (Pre-Deserialization): Validate and sanitize serialized data before deserialization to detect and reject potentially malicious payloads. Implement checks on data structure and content before passing to Boost.Serialization.
  • Restrict Deserialization Classes: If Boost.Serialization allows it (check documentation for version-specific features), restrict the classes that can be deserialized to a whitelist of safe, expected types.
  • Use Secure Serialization Alternatives: Consider using safer serialization formats like JSON or Protocol Buffers, which are generally less prone to object injection vulnerabilities by design.
  • Code Audits and Security Reviews: Thoroughly audit code that uses Boost.Serialization for potential deserialization vulnerabilities, focusing on the data sources and deserialization process.

Attack Surface: Format String Vulnerabilities (via Boost.Format)

• Description: Exploiting format string functions by providing user-controlled input as part of the format string, potentially leading to information disclosure or code execution.
• Boost Contribution: Boost.Format is vulnerable to format string attacks if user-controlled input is directly used as the format string. This is a direct consequence of how Boost.Format interprets format specifiers within the provided string.
• Example: Code uses boost::format(user_input) % ... where user_input is directly taken from user input. An attacker provides a format string like %s%s%s%s%n which could be used to read from or write to arbitrary memory locations, potentially leading to code execution.
• Impact: Information disclosure, code execution, denial of service.
• Risk Severity: High to Critical
• Mitigation Strategies:
  • Never Use User Input as Format String: Absolutely never directly use user-controlled input as the format string in Boost.Format. This is the primary and most critical mitigation.
  • Hardcode Format Strings: Use hardcoded, predefined format strings within the code. Only use user input as arguments to the format string, ensuring it is treated as data, not format specifiers.
  • Input Validation (if unavoidable user influence on format): If there's a very specific and controlled need for user input to influence formatting (which is highly discouraged for security reasons), extremely carefully validate and sanitize the input to ensure it cannot be interpreted as format specifiers. This is complex and error-prone, so avoid if possible.
  • Use Safer Alternatives: Consider using safer string formatting methods like std::stringstream or std::format (C++20 and later) if format string vulnerabilities are a major concern and Boost.Format's features are not strictly necessary.