attack-tree.md

Attack Tree Analysis for yhirose/cpp-httplib

Objective: Compromise application using cpp-httplib by exploiting vulnerabilities within the library itself.

Attack Tree Visualization

Attack Goal: Compromise Application using cpp-httplib └───[AND] Exploit cpp-httplib Vulnerabilities ├───[OR] Input Validation Flaws [HIGH RISK PATH] │ ├───[OR] Header Injection Attacks [HIGH RISK PATH] │ │ ├── CRLF Injection in Headers [CRITICAL NODE] │ │ └── Header Parameter Pollution [CRITICAL NODE] │ ├───[OR] URL Parsing Vulnerabilities [HIGH RISK PATH] │ │ ├── Path Traversal via URL Manipulation [CRITICAL NODE] │ │ └── Denial of Service via Malformed URLs [CRITICAL NODE] ├───[OR] Denial of Service (DoS) Attacks [HIGH RISK PATH] │ ├───[OR] Resource Exhaustion [HIGH RISK PATH] │ │ ├── Connection Exhaustion [CRITICAL NODE] │ │ ├── Memory Exhaustion [CRITICAL NODE] │ │ ├── CPU Exhaustion [CRITICAL NODE] │ │ └── Crash/Assert DoS [CRITICAL NODE]

Attack Tree Path: Input Validation Flaws [HIGH RISK PATH]

• This is a high-risk path because it targets the fundamental security principle of validating all external inputs. If cpp-httplib or the application using it fails to properly validate HTTP request components like headers and URLs, it opens the door to various attacks.

  • Header Injection Attacks [HIGH RISK PATH]:

    • This sub-path is high-risk because HTTP headers are often processed and interpreted by both the server and the application. Vulnerabilities here can lead to control over HTTP responses or manipulation of application logic.
      • CRLF Injection in Headers [CRITICAL NODE]:
        • Attack Vector: By injecting Carriage Return Line Feed (CRLF) characters (\r\n) into HTTP header values, an attacker can insert arbitrary headers or even the HTTP response body.
        • Exploitation: This can be used for:
          • Response Splitting: Injecting a full HTTP response to be delivered to the client, potentially bypassing security controls or injecting malicious content.
          • Cache Poisoning: Manipulating cached responses to serve malicious content to other users.
          • HTTP Request Smuggling (in some scenarios): Though less direct than dedicated smuggling techniques, CRLF injection can sometimes contribute to smuggling vulnerabilities.
          • Potential XSS: If headers are reflected in error messages or logs without proper encoding, CRLF injection could lead to Cross-Site Scripting (XSS).
      • Header Parameter Pollution [CRITICAL NODE]:
        • Attack Vector: If the application relies on parsing parameters from HTTP headers (e.g., custom headers or standard headers like Cookie, User-Agent if parsed in a non-standard way), an attacker can inject malicious parameters.
        • Exploitation: By injecting unexpected or malicious parameters, an attacker can influence application logic, potentially bypassing authentication, authorization, or other security checks. This depends heavily on how the application processes and trusts header parameters.

  • URL Parsing Vulnerabilities [HIGH RISK PATH]:

    • This sub-path is high-risk because URLs are the primary way users interact with web applications. Flaws in URL parsing can lead to unauthorized access or denial of service.
      • Path Traversal via URL Manipulation [CRITICAL NODE]:
        • Attack Vector: By crafting URLs containing special characters like ".." (dot-dot-slash), an attacker attempts to access files or directories outside of the intended web root.
        • Exploitation: If the application uses cpp-httplib to serve files based on URL paths and doesn't properly sanitize or validate these paths, an attacker can:
          • Access Sensitive Files: Read configuration files, source code, database credentials, or other sensitive data stored on the server.
          • Potentially Write Files (in some misconfigurations): In rare cases, path traversal vulnerabilities combined with other weaknesses could lead to writing files outside the intended directory.
      • Denial of Service via Malformed URLs [CRITICAL NODE]:
        • Attack Vector: Sending specially crafted URLs that are malformed, excessively long, or contain unusual characters can trigger parsing errors or excessive resource consumption in cpp-httplib or the application.
        • Exploitation: This can lead to:
          • CPU Exhaustion: Complex or inefficient URL parsing logic might be triggered by malformed URLs, leading to CPU overload.
          • Memory Exhaustion: Parsing very long URLs or URLs with specific patterns might consume excessive memory.
          • Crashes: Parsing errors or unhandled exceptions during URL processing could cause the application or cpp-httplib to crash.

Attack Tree Path: Denial of Service (DoS) Attacks [HIGH RISK PATH]

• This is a high-risk path because DoS attacks directly target the availability of the application, making it inaccessible to legitimate users. Even a temporary DoS can have significant business impact.

  • Resource Exhaustion [HIGH RISK PATH]:
    • This sub-path is high-risk as it encompasses several common and effective DoS techniques that aim to deplete server resources.
      • Connection Exhaustion [CRITICAL NODE]:
        • Attack Vector: An attacker sends a massive number of connection requests to the server, exceeding its connection limits and exhausting resources like file descriptors or thread pool capacity.
        • Exploitation: This prevents the server from accepting new connections from legitimate users, effectively denying service.
      • Memory Exhaustion [CRITICAL NODE]:
        • Attack Vector: Attackers send requests designed to consume excessive memory on the server. This could be through very large request bodies, numerous headers, or requests that trigger memory-intensive operations in the application or cpp-httplib.
        • Exploitation: Memory exhaustion leads to server slowdown, performance degradation, and eventually, potential crashes as the server runs out of memory.
      • CPU Exhaustion [CRITICAL NODE]:
        • Attack Vector: Attackers send requests that are computationally expensive to process, overloading the server's CPU. This could involve requests that trigger complex parsing, processing, or algorithmic operations within the application or cpp-httplib.
        • Exploitation: CPU exhaustion leads to server slowdown, performance degradation, and potentially service unavailability as the CPU becomes overloaded.
      • Crash/Assert DoS [CRITICAL NODE]:
        • Attack Vector: Attackers send malformed or unexpected requests that trigger bugs, unhandled exceptions, or assertions within cpp-httplib or the application code, leading to crashes or program termination.
        • Exploitation: A crash directly interrupts the service, making it unavailable until it is restarted. Repeated crashes can cause prolonged service disruption.

These High-Risk Paths and Critical Nodes represent the most immediate and easily exploitable threats related to using cpp-httplib. Focusing mitigation efforts on these areas will significantly improve the security posture of applications built with this library.