attack-tree.md

Attack Tree Analysis for impress/impress.js

Objective: Execute Arbitrary JavaScript in User's Browser via impress.js Presentation

Attack Tree Visualization

Goal: Execute Arbitrary JavaScript in User's Browser via impress.js Presentation

└── 1. Exploit impress.js Core Functionality ├── 1.1 Manipulate data-* Attributes [HIGH RISK] │ └── 1.1.4 Custom data-* attributes used by plugins or custom code. │ └── 1.1.4.2 Craft malicious payloads. [CRITICAL] ├── 1.2 Abuse Event Handlers [HIGH RISK] │ ├── 1.2.1 impress:stepenter, impress:stepleave, impress:init, etc. │ │ └── 1.2.1.2 Craft malicious input. [CRITICAL] │ └── 1.2.2 Custom event handlers. │ └── 1.2.2.2 Craft malicious input. [CRITICAL] └── 1.3 Manipulate URL Hash [HIGH RISK] ├── 1.3.1 Directly inject JavaScript into the URL hash. [CRITICAL] ├── 1.3.2 Use the hash to trigger vulnerable event handlers. [CRITICAL] └── 1.3.3 Use the hash to load a malicious external resource. [CRITICAL]

└── 2. Exploit impress.js Plugins [HIGH RISK] └── 2.3 Exploit Identified Vulnerabilities. [CRITICAL]

└── 3. Dependency Vulnerabilities [HIGH RISK] └── 3.3 Exploit Known Vulnerabilities. [CRITICAL]

Attack Tree Path: 1. Exploit impress.js Core Functionality

• 1.1 Manipulate data-* Attributes [HIGH RISK]

  • 1.1.4 Custom data-* attributes used by plugins or custom code:
    • Description: The application or a plugin uses custom data-* attributes (beyond the standard ones defined by impress.js) to store data that is later processed by JavaScript. If this processing doesn't include proper sanitization, an attacker can inject malicious JavaScript code into these attributes.
    • 1.1.4.2 Craft malicious payloads. [CRITICAL]
      • Description: The attacker crafts a malicious payload (e.g., <script>alert(1)</script>) and injects it into a custom data-* attribute. When the application processes this attribute, the injected JavaScript code is executed.
      • Example: If a plugin uses data-my-custom-attribute and processes it with element.innerHTML = element.dataset.myCustomAttribute;, an attacker could set data-my-custom-attribute="<img src=x onerror=alert(1)>" to trigger an XSS.
      • Mitigation: Use a robust HTML sanitizer (like DOMPurify) before using the value of any custom data-* attribute in JavaScript or inserting it into the DOM. Validate the data against an expected format.

• 1.2 Abuse Event Handlers [HIGH RISK]

  • 1.2.1 impress:stepenter, impress:stepleave, impress:init, etc.:
    • Description: impress.js provides built-in events. If the application registers event handlers for these events and those handlers execute code based on user-provided input without sanitization, an attacker can inject malicious code.
    • 1.2.1.2 Craft malicious input. [CRITICAL]
      • Description: The attacker crafts input (e.g., a URL parameter or data within the presentation content) that, when processed by the event handler, causes the execution of malicious JavaScript.
      • Example: If an event handler uses eval("console.log('" + someUserInput + "')");, an attacker could provide input like '); alert(1); // to execute arbitrary code.
      • Mitigation: Avoid using eval() or similar functions with user input. Sanitize any user input used within event handlers. Use a strict CSP to limit script execution.
  • 1.2.2 Custom event handlers:
    • Description: The application or a plugin defines its own custom event handlers. These are even more likely to be vulnerable than built-in event handlers if not carefully designed.
    • 1.2.2.2 Craft malicious input. [CRITICAL]
      • Description: Similar to 1.2.1.2, the attacker crafts input designed to exploit the custom event handler's logic.
      • Example: If a custom event handler takes a string from a data-* attribute and uses it as part of a URL, an attacker could inject JavaScript using a javascript: URL.
      • Mitigation: Same as 1.2.1.2: avoid eval(), sanitize input, and use a CSP.

• 1.3 Manipulate URL Hash [HIGH RISK]

  • 1.3.1 Directly inject JavaScript into the URL hash. [CRITICAL]
    • Description: The application uses the URL hash (the part of the URL after the #) to determine the active step or to retrieve data. If the application directly inserts the hash value into the DOM or uses it in eval() or similar without sanitization, an attacker can inject JavaScript code.
    • Example: If the application uses document.getElementById(window.location.hash.substring(1)).innerHTML = "Some content";, an attacker could use a URL like #"><script>alert(1)</script> to inject code.
    • Mitigation: Never directly insert the URL hash into the DOM or use it in eval(). Parse the hash and validate it against an expected format (e.g., a valid step ID). Use a robust HTML sanitizer if you must insert any part of the hash into the DOM.
  • 1.3.2 Use the hash to trigger vulnerable event handlers. [CRITICAL]
    • Description: The attacker crafts a URL with a hash that navigates to a specific step in the presentation. This step is designed (by the attacker or unintentionally by the developer) to trigger a vulnerable event handler (see 1.2).
    • Example: If step #badstep has a data-custom-attribute with a vulnerability, and an event handler processes that attribute on impress:stepenter, the attacker can use a URL like #badstep to trigger the XSS.
    • Mitigation: Combine the mitigations for 1.2 (secure event handlers) and 1.3.1 (safe hash handling).
  • 1.3.3 Use the hash to load a malicious external resource. [CRITICAL]
    • Description: A plugin or custom code allows loading external resources (images, scripts, etc.) based on the URL hash. The attacker crafts a URL with a hash that points to a malicious resource.
    • Example: If a plugin uses the hash to load an image: image.src = "images/" + window.location.hash.substring(1) + ".jpg";, an attacker could use a URL like #../../malicious-script to load a script instead.
    • Mitigation: Never construct URLs for external resources directly from the hash. Validate the hash against a whitelist of allowed values. Use a strict CSP to limit the sources from which resources can be loaded.

Attack Tree Path: 2. Exploit impress.js Plugins [HIGH RISK]

• 2.3 Exploit Identified Vulnerabilities. [CRITICAL]
  • Description: After identifying and analyzing loaded plugins (steps 2.1 and 2.2, not included in this sub-tree), the attacker crafts specific exploits targeting any vulnerabilities found in those plugins. This could involve any of the techniques described above (manipulating data-* attributes, abusing event handlers, etc.), but specifically within the context of the plugin's code.
  • Mitigation:
    • Thoroughly vet any plugins before using them. Prefer well-maintained and widely-used plugins.
    • Review the plugin's source code for security vulnerabilities.
    • Keep plugins updated to their latest versions.
    • Consider forking and maintaining your own version of a plugin if necessary.
    • Use a strict CSP to limit the plugin's capabilities.

Attack Tree Path: 3. Dependency Vulnerabilities [HIGH RISK]

• 3.3 Exploit Known Vulnerabilities. [CRITICAL]
  • Description: The application using impress.js (or impress.js itself, though less likely) has dependencies on other JavaScript libraries. These dependencies may have known security vulnerabilities. The attacker exploits these vulnerabilities to gain control of the application.
  • Mitigation:
    • Regularly check for and update dependencies using tools like npm audit, snyk, or OWASP Dependency-Check.
    • Use a Software Composition Analysis (SCA) tool to identify and manage dependencies.
    • Consider using a vulnerability scanner to automatically detect known vulnerabilities.