attack-tree.md

Attack Tree Analysis for yhirose/cpp-httplib

Objective: Compromise the application using cpp-httplib (specifically: Execute arbitrary code on the server, or cause a denial-of-service (DoS) by exploiting vulnerabilities or misconfigurations within cpp-httplib).

Attack Tree Visualization

                                      Compromise Application using cpp-httplib
                                                    |
        -------------------------------------------------------------------------------------------------
        |                                                                                               |
  1. Execute Arbitrary Code [CRITICAL]                                                     3. Denial of Service (DoS) [CRITICAL]
        |                                                                                               |
  --------------                                                                                ---------------------
  |                                                                                                   |                   |
1.1 Buffer                                                                                       3.1 Resource       3.2 Logic
Overflow                                                                                         Exhaustion        Flaws
[HIGH RISK]                                                                                       [CRITICAL]         |
  [CRITICAL]                                                                                                          |
                                                                                                                |
                                                                                                            --------------
                                                                                                            |            |
                                                                                                         3.1.2       3.2.2
                                                                                                            CPU         Slow
                                                                                                       Intensive     Loris
                                                                                                       Operations  (Header
                                                                                                       [HIGH RISK]  Manipulation)
                                                                                                                    [HIGH RISK]

Attack Tree Path: 1. Execute Arbitrary Code [CRITICAL]

• Description: This represents the attacker's ability to run arbitrary code of their choosing on the server hosting the application. This is the most severe outcome, granting the attacker full control.
• Why Critical: Complete system compromise. The attacker can do anything the application's user account can do, including reading, modifying, or deleting data, installing malware, and potentially pivoting to other systems.

Attack Tree Path: 1.1 Buffer Overflow [HIGH RISK] [CRITICAL]

• Description: An attacker sends a crafted request (e.g., with an overly long header or body) that exceeds the size of a buffer allocated by cpp-httplib. This overwrites adjacent memory, potentially including return addresses or function pointers, allowing the attacker to redirect execution to their own malicious code.
• Why High Risk: Classic, high-impact vulnerability. While mitigated by modern C++ practices, it remains a significant threat if any manual memory management or unsafe functions are used.
• Likelihood: Low (Modern C++ practices reduce this, but it's not impossible)
• Impact: Very High (Complete system compromise)
• Effort: Medium to High (Requires finding and exploiting the vulnerability)
• Skill Level: Advanced
• Detection Difficulty: Medium to Hard (Can be detected by fuzzing, static analysis, or runtime errors, but might go unnoticed initially)

Attack Tree Path: 3. Denial of Service (DoS) [CRITICAL]

• Description: The attacker prevents legitimate users from accessing the application by making it unavailable.
• Why Critical: Directly impacts the application's core functionality and availability.

Attack Tree Path: 3.1 Resource Exhaustion [CRITICAL]

• Description: The attacker consumes server resources (CPU, memory, network connections) to the point where the application can no longer function. * Why Critical: Encompasses multiple common and effective DoS attack vectors.

Attack Tree Path: 3.1.2 CPU Intensive Operations [HIGH RISK]

• Description: The attacker sends requests designed to trigger computationally expensive operations within cpp-httplib (e.g., complex regular expressions, inefficient parsing, or algorithmic complexity vulnerabilities). This consumes excessive CPU cycles, slowing down or completely halting the server's ability to process legitimate requests. * Why High Risk: Relatively easy to exploit if such operations are exposed and can have a significant impact on availability. * Likelihood: Medium (Depends on the presence of computationally expensive operations) * Impact: Medium to High (Slowdown or unresponsiveness) * Effort: Low to Medium (Crafting requests to trigger expensive operations) * Skill Level: Novice to Intermediate * Detection Difficulty: Medium (High CPU usage is noticeable)

Attack Tree Path: 3.2 Logic Flaws

• Description: Exploiting flaws in the application or library's logic to cause a denial of service.

Attack Tree Path: 3.2.2 Slow Loris (Header Manipulation) [HIGH RISK]

• Description: The attacker establishes multiple connections to the server but sends HTTP request headers very slowly, one small piece at a time. If cpp-httplib doesn't have appropriate timeouts or connection management, these slow connections can tie up server resources (e.g., connection slots in a thread pool), preventing legitimate clients from connecting. * Why High Risk: Easy to execute with readily available tools, and highly effective against servers without proper mitigation. * Likelihood: Medium (Depends on connection handling and timeouts) * Impact: High (Can exhaust connection pool) * Effort: Low (Tools readily available) * Skill Level: Novice * Detection Difficulty: Medium to Hard (Requires monitoring connection states; can be mitigated by reverse proxies)