attack-tree.md

Attack Tree Analysis for openresty/lua-nginx-module

Objective: Gain unauthorized access, control, or disrupt the application by exploiting vulnerabilities or weaknesses introduced by the Lua-Nginx-Module.

Attack Tree Visualization

Compromise Application via Lua-Nginx-Module [CRITICAL NODE]
├───[OR] Exploit Lua Code Vulnerabilities [CRITICAL NODE] [HIGH-RISK]
│   ├───[OR] Lua Injection Vulnerabilities [CRITICAL NODE] [HIGH-RISK]
│   │   ├───[AND] Input Manipulation
│   │   │   ├───[AND] Identify Input Vectors
│   │   │   └───[AND] Inject Malicious Lua Code [HIGH-RISK]
│   │   └───[AND] Code Execution [CRITICAL NODE]
│   │       └───[AND] Execute Arbitrary Lua Code on Server [CRITICAL NODE]
│   │           └───[Goal Achieved: Code Execution] [CRITICAL NODE]
│   ├───[OR] Logic Errors in Lua Code [HIGH-RISK]
│   │   ├───[AND] Identify Logic Flaws [HIGH-RISK]
│   │   ├───[AND] Trigger Vulnerable Logic Flow [HIGH-RISK]
│   │   └───[AND] Exploit Logic Flaws [HIGH-RISK]
│   │       ├───[OR] Data Breach [HIGH-RISK]
│   │       └───[OR] Application Manipulation [HIGH-RISK]
│   ├───[OR] Vulnerable Lua Libraries [HIGH-RISK]
│   │   ├───[AND] Identify Used Lua Libraries
│   │   ├───[AND] Check for Known Vulnerabilities
│   │   └───[AND] Exploit Library Vulnerabilities [HIGH-RISK]
│   │       ├───[OR] Code Execution [HIGH-RISK]
│   │       └───[OR] Data Breach [HIGH-RISK]
│   └───[OR] Denial of Service (DoS) via Lua [HIGH-RISK]
│       ├───[AND] Resource Exhaustion [HIGH-RISK]
│       │   ├───[AND] Craft Malicious Request [HIGH-RISK]
│       │   │   └───[AND] Design request to trigger resource-intensive Lua operations [HIGH-RISK]
│       │   └───[AND] Send Malicious Request(s) [HIGH-RISK]
│       └───[AND] Application Unavailability [CRITICAL NODE]
│           └───[Goal Achieved: DoS] [CRITICAL NODE]
├───[OR] Exploit Nginx Configuration Issues (Lua Related) [HIGH-RISK]
│   ├───[OR] Insecure `lua_package_path`/`lua_package_cpath` [HIGH-RISK]
│   │   ├───[AND] Identify Package Paths
│   │   ├───[AND] Write Access to Package Paths [HIGH-RISK]
│   │   │   └───[AND] Determine if attacker can write to directories specified in package paths [HIGH-RISK]
│   │   └───[AND] Plant Malicious Lua Modules [HIGH-RISK]
│   │       ├───[AND] Upload Malicious Lua File [HIGH-RISK]
│   │       │   └───[AND] Upload a Lua file with malicious code to a writable package path [HIGH-RISK]
│   │       └───[AND] Trigger Module Loading [HIGH-RISK]
│   │           └───[AND] Application loads the malicious module via `require` [HIGH-RISK]
│   │               └───[Goal Achieved: Code Execution] [CRITICAL NODE]
│   ├───[OR] Exposing Internal APIs via Lua [HIGH-RISK]
│   │   ├───[AND] Identify Exposed APIs [HIGH-RISK]
│   │   │   └───[AND] Analyze Lua scripts for usage of Nginx internal APIs [HIGH-RISK]
│   │   ├───[AND] Access Exposed APIs [HIGH-RISK]
│   │   │   └───[AND] Craft requests or Lua code to access and exploit exposed internal APIs [HIGH-RISK]
│   │   └───[AND] Exploit Exposed APIs [HIGH-RISK]
│   │       ├───[OR] Information Disclosure [HIGH-RISK]
│   │       └───[OR] Configuration Manipulation [HIGH-RISK]
│   └───[OR] Misconfigured `content_by_lua*`, `access_by_lua*`, etc. [HIGH-RISK] [CRITICAL NODE]
│       ├───[AND] Identify Misconfigurations [HIGH-RISK]
│       │   └───[AND] Analyze Nginx configuration for incorrect or overly permissive usage of `content_by_lua*`, `access_by_lua*`, etc. [HIGH-RISK]
│       ├───[AND] Exploit Misconfiguration [HIGH-RISK]
│       │   └───[AND] Leverage misconfiguration to inject or execute malicious Lua code or bypass intended security controls [HIGH-RISK]
│       └───[AND] Gain Control [CRITICAL NODE]
│           ├───[OR] Code Execution [CRITICAL NODE] [HIGH-RISK]
│           └───[OR] Access Control Bypass [HIGH-RISK]

Attack Tree Path: Compromise Application via Lua-Nginx-Module [CRITICAL NODE]

This is the root goal. Success means the attacker has achieved unauthorized access, control, or disruption of the application due to vulnerabilities related to Lua-Nginx-Module.

Attack Tree Path: Exploit Lua Code Vulnerabilities [CRITICAL NODE] [HIGH-RISK]

This category encompasses vulnerabilities arising from the Lua code written for the application.

Attack Tree Path: Lua Injection Vulnerabilities [CRITICAL NODE] [HIGH-RISK]

Attack Vector: Injecting malicious Lua code through user-controlled input that is then executed by the application (e.g., using ngx.eval, loadstring, or string concatenation). * Impact: Arbitrary code execution on the server.

Attack Tree Path: Logic Errors in Lua Code [HIGH-RISK]

Attack Vector: Exploiting flaws in the application's business logic implemented in Lua (e.g., authentication bypass, authorization flaws, insecure data handling). * Impact: Data breach, application manipulation, unauthorized actions.

Attack Tree Path: Vulnerable Lua Libraries [HIGH-RISK]

Attack Vector: Exploiting known vulnerabilities in third-party Lua libraries used by the application. * Impact: Code execution, data breach, depending on the library vulnerability.

Attack Tree Path: Denial of Service (DoS) via Lua [HIGH-RISK]

Attack Vector: Crafting malicious requests that trigger resource-intensive Lua operations (e.g., infinite loops, excessive memory allocation) leading to server overload. * Impact: Application unavailability, service disruption.

Attack Tree Path: Exploit Nginx Configuration Issues (Lua Related) [HIGH-RISK]

This category focuses on vulnerabilities arising from misconfigurations in Nginx that are specific to its interaction with Lua-Nginx-Module.

Attack Tree Path: Insecure lua_package_path/lua_package_cpath [HIGH-RISK]

Attack Vector: If lua_package_path or lua_package_cpath points to writable directories, attackers can upload malicious Lua modules and force the application to load and execute them. * Impact: Code execution on the server.

Attack Tree Path: Exposing Internal APIs via Lua [HIGH-RISK]

Attack Vector: Unintentionally exposing Nginx internal APIs (e.g., ngx.config, ngx.shared.DICT) through Lua scripts, allowing attackers to access sensitive information or manipulate Nginx internals. * Impact: Information disclosure (Nginx configuration, shared data), configuration manipulation, potentially leading to further compromise.

Attack Tree Path: Misconfigured content_by_lua*, access_by_lua*, etc. [CRITICAL NODE] [HIGH-RISK]

Attack Vector: Incorrect or overly permissive usage of Nginx directives like content_by_lua*, access_by_lua*, etc., such as directly executing untrusted Lua code or bypassing intended security controls. * Impact: Code execution, access control bypass, potentially full application control.

Attack Tree Path: Code Execution [CRITICAL NODE]

This is a critical node representing the achievement of arbitrary code execution on the server. It is the highest impact outcome for many attack paths.

Attack Tree Path: Execute Arbitrary Lua Code on Server [CRITICAL NODE]

This is the specific action that leads to Code Execution.

Attack Tree Path: Goal Achieved: Code Execution [CRITICAL NODE]

This marks the successful achievement of the Code Execution goal.

Attack Tree Path: Application Unavailability [CRITICAL NODE]

This is a critical node representing the state of the application being unavailable due to a successful Denial of Service attack.

Attack Tree Path: Goal Achieved: DoS [CRITICAL NODE]

This marks the successful achievement of the Denial of Service goal.

Attack Tree Path: Gain Control [CRITICAL NODE] (under Misconfigured content_by_lua*)

This node represents the attacker gaining control over the application due to misconfigurations, which can manifest as Code Execution or Access Control Bypass.