attack-tree.md

Attack Tree Analysis for nwjs/nw.js

Objective: To achieve arbitrary code execution on the user's machine, gain access to local system resources, or exfiltrate sensitive data by exploiting vulnerabilities inherent in the nw.js framework or its interaction with the application.

Attack Tree Visualization

• **[CRITICAL NODE] Compromise nw.js Application
  • [OR] **[HIGH-RISK PATH] Exploit Chromium Vulnerabilities
    • [AND] **[HIGH-RISK PATH] Trigger Vulnerable Code Path in Application's Web Content
      • Action: Analyze application's web code for interactions that might trigger browser vulnerabilities (e.g., complex JavaScript, DOM manipulation).
  • [OR] **[CRITICAL NODE] Exploit Browser Feature Misconfiguration
    • [AND] **[CRITICAL NODE] Insecure node-remote Usage
      • [AND] **[HIGH-RISK PATH] Enable node-remote for Untrusted Origins
        • Action: Critical: Never enable node-remote for untrusted or external origins. Restrict to localhost or trusted internal resources only.
      • [AND] **[HIGH-RISK PATH] Fail to Sanitize Input from node-remote Context
        • Action: Sanitize all data received from node-remote contexts before using in Node.js APIs.
    • [AND] **[HIGH-RISK PATH] Load Untrusted Content in webview with Node.js Integration
      • Action: Only load trusted content in webview if nodeIntegration is enabled. Treat webview content with the same caution as external websites.
  • [OR] **[CRITICAL NODE] Exploit Node.js Integration Vulnerabilities
    • [AND] **[CRITICAL NODE] Abuse nw.js Node.js APIs Directly
      • [AND] **[CRITICAL NODE] Exploit Insecure Use of child_process
        • [AND] **[HIGH-RISK PATH] Execute Arbitrary Commands via child_process.exec or similar
          • Action: Critical: Avoid using child_process.exec with unsanitized user input. Use safer alternatives like child_process.spawn with carefully constructed arguments.
        • [AND] **[HIGH-RISK PATH] Command Injection via Unsanitized Input to child_process
          • Action: Sanitize and validate all input before passing to child_process functions. Use parameterized commands where possible.
      • [AND] **[CRITICAL NODE] Exploit File System Access Vulnerabilities
        • [AND] **[HIGH-RISK PATH] Path Traversal via fs module
          • Action: Sanitize file paths to prevent path traversal attacks. Use absolute paths or restrict access to specific directories.
      • [AND] **[CRITICAL NODE] Exploit Network API Misuse
        • [AND] **[HIGH-RISK PATH] Server-Side Request Forgery (SSRF) via Node.js HTTP/Network Modules
          • Action: Sanitize and validate URLs used in Node.js network requests. Implement allowlists for external domains if necessary.
      • [AND] **[CRITICAL NODE] Exploit Insecure Dependencies in Node.js Backend
        • [AND] **[HIGH-RISK PATH] Use Vulnerable npm Packages
          • Action: Regularly audit and update npm dependencies. Use tools like npm audit or snyk to identify and fix vulnerabilities.
    • [AND] **[CRITICAL NODE] Expose Node.js Functionality to Web Context Insecurely
      • [AND] **[CRITICAL NODE] Expose Node.js APIs via window.nw without Proper Security
        • [AND] **[HIGH-RISK PATH] Directly Expose Sensitive Node.js Modules to window.nw
          • Action: Critical: Avoid directly exposing Node.js modules to the window.nw object unless absolutely necessary. If needed, create minimal, secure wrappers.
        • [AND] **[HIGH-RISK PATH] Fail to Sanitize Data Passed Between Web and Node.js Contexts
          • Action: Sanitize and validate all data passed between the web context and Node.js context, especially when using window.nw.call or similar mechanisms.
  • [OR] **[CRITICAL NODE] Packaging and Distribution Vulnerabilities
    • [AND] **[CRITICAL NODE] Insecure Update Mechanisms
      • [AND] **[HIGH-RISK PATH] Man-in-the-Middle Attacks on Update Channels
        • Action: Use HTTPS for update channels and implement certificate pinning or similar mechanisms to prevent MITM attacks.

Attack Tree Path: Exploit Chromium Vulnerabilities -> Trigger Vulnerable Code Path in Application's Web Content

Attack Vector: An attacker identifies a known vulnerability in the version of Chromium used by nw.js. They then craft malicious web content (JavaScript, HTML, CSS) that, when loaded by the application, triggers this vulnerability. * Exploitation: This could involve exploiting memory corruption bugs, logic errors in browser features, or vulnerabilities in JavaScript engines. * Impact: Arbitrary code execution within the Chromium renderer process, potentially leading to system compromise if renderer sandbox is bypassed or if combined with other vulnerabilities. * Mitigation: Keep nw.js updated to benefit from Chromium security patches. Thoroughly test application's web content for potential interactions that could trigger browser vulnerabilities.

Attack Tree Path: Exploit Browser Feature Misconfiguration -> Insecure node-remote Usage -> Enable node-remote for Untrusted Origins

Attack Vector: Developers mistakenly enable the node-remote feature for origins they do not fully trust (e.g., external websites, user-provided URLs). * Exploitation: Malicious content from these untrusted origins can then directly execute Node.js code within the application's context, bypassing the usual web browser security sandbox. * Impact: Full system compromise, as the attacker gains direct access to Node.js APIs and can perform any action on the user's machine. * Mitigation: Never enable node-remote for untrusted origins. Restrict its use to localhost or strictly controlled internal resources. Regularly review nw.js configuration to ensure node-remote is properly configured.

Attack Tree Path: Exploit Browser Feature Misconfiguration -> Insecure node-remote Usage -> Fail to Sanitize Input from node-remote Context

Attack Vector: Even if node-remote is restricted to trusted origins, developers might fail to properly sanitize data received from the node-remote context before using it in Node.js APIs. * Exploitation: An attacker can inject malicious data through the node-remote communication channel. If this unsanitized data is used in vulnerable Node.js APIs (e.g., child_process, fs), it can lead to command injection, path traversal, or other vulnerabilities. * Impact: Arbitrary code execution, file system access, or other actions depending on the vulnerable Node.js API used with unsanitized input. * Mitigation: Sanitize and validate all data received from node-remote contexts before using it in Node.js APIs. Treat data from node-remote as potentially untrusted.

Attack Tree Path: Exploit Browser Feature Misconfiguration -> Load Untrusted Content in webview with Node.js Integration

Attack Vector: Developers load untrusted or external web content within a <webview> tag and mistakenly enable nodeIntegration for that <webview>. * Exploitation: Malicious content loaded in the <webview> can then directly access Node.js APIs due to nodeIntegration being enabled, bypassing the security sandbox intended for external content. * Impact: Full system compromise, similar to enabling node-remote for untrusted origins. * Mitigation: Only load trusted content in <webview> if nodeIntegration is enabled. If loading untrusted content is necessary, never enable nodeIntegration. Treat content loaded in <webview> with nodeIntegration enabled with the same caution as the main application's web content.

Attack Tree Path: Exploit Node.js Integration Vulnerabilities -> Abuse nw.js Node.js APIs Directly -> Exploit Insecure Use of child_process -> Execute Arbitrary Commands via child_process.exec or similar

Attack Vector: The application uses child_process.exec or similar functions to execute system commands, and the command string is constructed using unsanitized user input or data from untrusted sources. * Exploitation: An attacker can inject malicious commands into the command string. When child_process.exec is executed, these injected commands will be executed by the system. * Impact: Arbitrary command execution on the user's system, leading to full system compromise. * Mitigation: Avoid using child_process.exec with unsanitized input. Use safer alternatives like child_process.spawn and carefully construct command arguments, ideally using parameterized commands or escaping user input rigorously.

Attack Tree Path: Exploit Node.js Integration Vulnerabilities -> Abuse nw.js Node.js APIs Directly -> Exploit Insecure Use of child_process -> Command Injection via Unsanitized Input to child_process

Attack Vector: Similar to the previous point, but focuses on command injection vulnerabilities in general when using child_process functions. Even when using child_process.spawn, if arguments are not properly sanitized or constructed, injection can occur. * Exploitation: Attackers inject malicious arguments or shell metacharacters into the command or its arguments. * Impact: Arbitrary command execution, system compromise. * Mitigation: Sanitize and validate all input before passing it to child_process functions. Use parameterized commands where possible. Avoid constructing commands dynamically from user input.

Attack Tree Path: Exploit Node.js Integration Vulnerabilities -> Abuse nw.js Node.js APIs Directly -> Exploit File System Access Vulnerabilities -> Path Traversal via fs module

Attack Vector: The application uses the fs module to access files based on user-provided file paths or paths derived from untrusted sources, without proper sanitization. * Exploitation: An attacker can use path traversal techniques (e.g., ../, ..%2f) to manipulate file paths and access files outside of the intended directory or access restricted system files. * Impact: Unauthorized file access, data disclosure, potential data modification or deletion, denial of service. * Mitigation: Sanitize file paths to prevent path traversal attacks. Use absolute paths or restrict file access to specific, controlled directories. Validate user-provided file paths rigorously.

Attack Tree Path: Exploit Node.js Integration Vulnerabilities -> Abuse nw.js Node.js APIs Directly -> Exploit Network API Misuse -> Server-Side Request Forgery (SSRF) via Node.js HTTP/Network Modules

Attack Vector: The application uses Node.js HTTP or network modules to make requests to URLs that are influenced by user input or data from untrusted sources, without proper validation. * Exploitation: An attacker can manipulate the URL to make the application send requests to internal network resources, external websites, or services that the attacker would not normally be able to access directly. * Impact: Access to internal networks, data exfiltration from internal services, potential denial of service of internal or external services. * Mitigation: Sanitize and validate URLs used in Node.js network requests. Implement allowlists for allowed domains or protocols. Avoid directly using user input to construct URLs without validation.

Attack Tree Path: Exploit Node.js Integration Vulnerabilities -> Exploit Insecure Dependencies in Node.js Backend -> Use Vulnerable npm Packages

Attack Vector: The application relies on npm packages that contain known security vulnerabilities. * Exploitation: Attackers can exploit these vulnerabilities in the dependencies to compromise the application. Vulnerabilities in npm packages can range from information disclosure to remote code execution. * Impact: Depends on the specific vulnerability in the npm package, can range from information disclosure to arbitrary code execution and system compromise. * Mitigation: Regularly audit and update npm dependencies. Use tools like npm audit or snyk to identify and fix vulnerabilities. Implement a process for monitoring and patching dependency vulnerabilities.

Attack Tree Path: Exploit Node.js Integration Vulnerabilities -> Expose Node.js Functionality to Web Context Insecurely -> Expose Node.js APIs via window.nw without Proper Security -> Directly Expose Sensitive Node.js Modules to window.nw

Attack Vector: Developers directly expose sensitive Node.js modules (e.g., fs, child_process, os) to the web context through window.nw without proper security considerations. * Exploitation: Malicious JavaScript code running in the web context can then directly access these powerful Node.js modules and perform privileged operations on the user's system. * Impact: Full system compromise, as the web context gains direct access to Node.js capabilities. * Mitigation: Avoid directly exposing Node.js modules to the window.nw object unless absolutely necessary. If Node.js functionality needs to be exposed to the web context, create minimal, secure wrapper APIs in Node.js that perform specific, validated actions and expose only these limited APIs to the web context.

Attack Tree Path: Exploit Node.js Integration Vulnerabilities -> Expose Node.js Functionality to Web Context Insecurely -> Expose Node.js APIs via window.nw without Proper Security -> Fail to Sanitize Data Passed Between Web and Node.js Contexts

Attack Vector: Even when using wrapper APIs to expose Node.js functionality, developers might fail to properly sanitize data passed between the web context and the Node.js context. * Exploitation: An attacker can inject malicious data from the web context when calling Node.js wrapper APIs. If this unsanitized data is used in vulnerable Node.js operations, it can lead to injection vulnerabilities, privilege escalation, or other issues. * Impact: Depends on the vulnerability, can range from data manipulation to arbitrary code execution in the Node.js context. * Mitigation: Sanitize and validate all data passed between the web context and the Node.js context, especially when using window.nw.call or similar mechanisms. Treat data from the web context as potentially untrusted.

Attack Tree Path: Packaging and Distribution Vulnerabilities -> Insecure Update Mechanisms -> Man-in-the-Middle Attacks on Update Channels

Attack Vector: The application uses an insecure update mechanism that does not properly protect against Man-in-the-Middle (MITM) attacks. This often involves using unencrypted HTTP for update downloads or failing to verify the integrity and authenticity of updates. * Exploitation: An attacker can intercept the update communication channel (e.g., by performing a network MITM attack) and inject a malicious update package. * Impact: Widespread malware distribution, as users who update their application will download and install the malicious update, leading to system compromise on a large scale. * Mitigation: Use HTTPS for all update communication channels. Implement certificate pinning to prevent MITM attacks. Always verify the integrity and authenticity of updates before applying them using digital signatures and checksums. Ensure the update process is secure and robust.