attack-tree.md

Attack Tree Analysis for naptha/tesseract.js

Objective: Compromise application using tesseract.js by exploiting vulnerabilities within tesseract.js.

Attack Tree Visualization

Compromise Application via tesseract.js **[CRITICAL NODE]**
├───(OR)─ **[HIGH RISK PATH]** Exploit Vulnerabilities in Image Processing **[CRITICAL NODE]**
│   ├───(OR)─ **[HIGH RISK PATH]** Image Parsing Vulnerabilities **[CRITICAL NODE]**
│   │   ├───(AND)─ Malformed Image Input + Vulnerable Image Parsing Logic
│   │   │   ├─── **[HIGH RISK PATH]** Buffer Overflow during Image Decoding **[CRITICAL NODE]**
│   │   │   │   └───(Actionable Insight) Input sanitization and validation on image data. Use safe image decoding libraries if possible. Consider sandboxing image processing.
│   │   │   ├─── **[HIGH RISK PATH]** Integer Overflow leading to Memory Corruption **[CRITICAL NODE]**
│   │   │   │   └───(Actionable Insight) Implement checks for image dimensions and sizes before processing. Review tesseract.js code for integer handling in image processing.
│   │   │   ├─── Format String Vulnerability (Less likely in JS, but theoretically possible in WASM/Native bindings if any) **[CRITICAL NODE]**
│   │   │   │   └───(Actionable Insight) Review any WASM or native code interactions for potential format string issues. Ensure proper input handling in these layers.
│   │   └───(AND)─ Exploitable Image Format Vulnerability + Lack of Input Validation
│   │       ├─── Use of Image Formats with Known Vulnerabilities (e.g., older versions of JPEG, PNG libraries) **[CRITICAL NODE]**
│   │       │   └───(Actionable Insight) Ensure tesseract.js and its dependencies use up-to-date and secure image processing libraries.
│   ├───(OR)─ Vulnerabilities in Image Processing Logic
│   │   └───(AND)─ Exploiting Specific Image Processing Steps
│   │       ├─── Vulnerabilities in Noise Reduction Algorithms **[CRITICAL NODE]**
│   │       │   └───(Actionable Insight) Research known vulnerabilities in noise reduction algorithms used by Tesseract and check if tesseract.js is susceptible.
│   │       ├─── Vulnerabilities in Skew Correction Algorithms **[CRITICAL NODE]**
│   │       │   └───(Actionable Insight) Research known vulnerabilities in skew correction algorithms used by Tesseract and check if tesseract.js is susceptible.
│   │       └─── Vulnerabilities in Segmentation Algorithms **[CRITICAL NODE]**
│   │           └───(Actionable Insight) Research known vulnerabilities in segmentation algorithms used by Tesseract and check if tesseract.js is susceptible.
├───(OR)─ Exploit Vulnerabilities in Text Recognition Logic
│   ├───(AND)─ Crafted Image Input + Vulnerability in OCR Engine
│   │   ├─── Exploiting Dictionary or Language Model Vulnerabilities (if applicable in tesseract.js context) **[CRITICAL NODE]**
│   │   │   └───(Actionable Insight) Investigate if tesseract.js uses dictionaries or language models that could be manipulated or exploited.
├───(OR)─ **[HIGH RISK PATH]** Exploit Dependencies or Underlying Tesseract Library Vulnerabilities **[CRITICAL NODE]**
│   ├───(AND)─ Vulnerable Tesseract Core + Exposed via tesseract.js
│   │   ├─── **[HIGH RISK PATH]** Known Vulnerabilities in Tesseract (C++ Library) **[CRITICAL NODE]**
│   │   │   └───(Actionable Insight) Regularly check for known vulnerabilities in the core Tesseract library. Ensure tesseract.js is using a patched and up-to-date version of Tesseract or its WASM port.
│   │   ├─── Vulnerabilities Introduced during Porting to JavaScript/WASM **[CRITICAL NODE]**
│   │   │   └───(Actionable Insight) Review the tesseract.js codebase and WASM compilation process for potential vulnerabilities introduced during porting from C++ to JavaScript/WASM.
│   │   └─── Insecure Configuration or Compilation of Tesseract WASM **[CRITICAL NODE]**
│   │       └───(Actionable Insight) Ensure the WASM build process for tesseract.js is secure and doesn't introduce vulnerabilities. Verify integrity of downloaded WASM files.
├───(OR)─ **[HIGH RISK PATH]** Client-Side Specific Attacks related to tesseract.js Usage **[CRITICAL NODE]**
│   ├───(AND)─ Malicious JavaScript Injection + Targeting tesseract.js Functionality
│   │   ├─── **[HIGH RISK PATH]** Cross-Site Scripting (XSS) to Manipulate tesseract.js Input **[CRITICAL NODE]**
│   │   │   └───(Actionable Insight) Implement robust XSS prevention measures in the application. Sanitize user inputs and outputs. Use Content Security Policy (CSP).
│   │   ├─── **[HIGH RISK PATH]** DOM Manipulation to Feed Malicious Images to tesseract.js **[CRITICAL NODE]**
│   │   │   └───(Actionable Insight) Secure the application against DOM-based XSS. Validate image sources and origins.
│   │   └─── Man-in-the-Middle (MITM) Attack to Replace tesseract.js Library with Malicious Version **[CRITICAL NODE]**
│   │       └───(Actionable Insight) Use HTTPS to serve the application and tesseract.js. Implement Subresource Integrity (SRI) to verify the integrity of tesseract.js files.

Attack Tree Path: 1. Exploit Vulnerabilities in Image Processing (High-Risk Path & Critical Node):

• Image Parsing Vulnerabilities (High-Risk Path & Critical Node):

  • Buffer Overflow during Image Decoding (High-Risk Path & Critical Node):
    • Attack Vector: Attacker crafts a malformed image that, when parsed by tesseract.js's image decoding logic, causes a buffer overflow. This can overwrite adjacent memory regions, potentially leading to code execution.
    • Actionable Insight: Implement robust input sanitization and validation on image data. Utilize safe and well-vetted image decoding libraries. Consider sandboxing the image processing environment to limit the impact of potential vulnerabilities.
  • Integer Overflow leading to Memory Corruption (High-Risk Path & Critical Node):
    • Attack Vector: Attacker provides an image with dimensions or metadata designed to trigger an integer overflow during image processing calculations. This overflow can lead to memory corruption and potentially code execution.
    • Actionable Insight: Implement thorough checks for image dimensions and sizes before processing. Review tesseract.js code, especially WASM/native bindings, for integer handling vulnerabilities in image processing routines.
  • Format String Vulnerability (Less likely in JS, but theoretically possible in WASM/Native bindings if any) (Critical Node):
    • Attack Vector: If tesseract.js or its underlying libraries (especially in WASM/native layers) use format strings without proper sanitization of user-controlled input (e.g., image metadata), an attacker could inject format string specifiers to read from or write to arbitrary memory locations, potentially leading to code execution.
    • Actionable Insight: Carefully review any WASM or native code interactions within tesseract.js for potential format string vulnerabilities. Ensure proper input handling and sanitization in these layers.

• Use of Image Formats with Known Vulnerabilities (e.g., older versions of JPEG, PNG libraries) (Critical Node):

  • Attack Vector: If tesseract.js relies on outdated or vulnerable image processing libraries for specific formats (like older versions of JPEG or PNG libraries), attackers can exploit known vulnerabilities in these libraries by providing images in those formats.
  • Actionable Insight: Ensure that tesseract.js and all its dependencies, especially image processing libraries, are kept up-to-date with the latest security patches. Regularly audit dependencies for known vulnerabilities.

• Vulnerabilities in Noise Reduction Algorithms (Critical Node):

  • Attack Vector: Noise reduction algorithms, while intended to improve OCR accuracy, might have algorithmic flaws or vulnerabilities. Attackers could craft images that exploit these vulnerabilities, potentially leading to unexpected behavior, denial of service, or even memory corruption depending on the nature of the flaw.
  • Actionable Insight: Research known vulnerabilities in noise reduction algorithms used by Tesseract (the underlying library) and assess if tesseract.js is susceptible. Consider fuzzing and security testing specifically targeting noise reduction functionalities.

• Vulnerabilities in Skew Correction Algorithms (Critical Node):

  • Attack Vector: Similar to noise reduction, skew correction algorithms could have vulnerabilities. Crafted images designed to trigger edge cases or flaws in these algorithms could lead to exploitable conditions.
  • Actionable Insight: Research known vulnerabilities in skew correction algorithms used by Tesseract and assess if tesseract.js is susceptible. Security testing should include images with varying degrees of skew and complex backgrounds to probe for vulnerabilities.

• Vulnerabilities in Segmentation Algorithms (Critical Node):

  • Attack Vector: Image segmentation, the process of separating text regions from background, is a complex step in OCR. Vulnerabilities in segmentation algorithms could be exploited with crafted images to cause incorrect segmentation, denial of service, or potentially memory corruption if flaws exist in the algorithm's implementation.
  • Actionable Insight: Research known vulnerabilities in segmentation algorithms used by Tesseract and assess if tesseract.js is susceptible. Test with images containing complex layouts, noise, and varying text densities to identify potential segmentation vulnerabilities.

Attack Tree Path: 2. Exploit Dictionary or Language Model Vulnerabilities (if applicable in tesseract.js context) (Critical Node):

• Attack Vector: If tesseract.js utilizes dictionaries or language models to improve OCR accuracy (e.g., for spell checking or context-aware recognition), these models themselves could be vulnerable. Attackers might attempt to inject malicious data into these models (if they are dynamically loaded or updated) or exploit vulnerabilities in the model parsing or loading process. This could potentially lead to manipulation of OCR results or, in more severe cases, code execution if model loading is insecure.
• Actionable Insight: Investigate whether tesseract.js uses dictionaries or language models that could be manipulated or exploited. If so, ensure that these models are loaded from trusted sources, integrity is verified, and the loading process is secure.

Attack Tree Path: 3. Exploit Dependencies or Underlying Tesseract Library Vulnerabilities (High-Risk Path & Critical Node):

• Known Vulnerabilities in Tesseract (C++ Library) (High-Risk Path & Critical Node):

  • Attack Vector: The core Tesseract library (written in C++) is a large and complex codebase. Known vulnerabilities in the C++ library can be exposed through tesseract.js, especially if tesseract.js uses a vulnerable version of the Tesseract library or its WASM port.
  • Actionable Insight: Implement a process for regularly checking for known vulnerabilities in the core Tesseract library (CVE databases, security advisories). Ensure that tesseract.js is using a patched and up-to-date version of Tesseract or its WASM port.

• Vulnerabilities Introduced during Porting to JavaScript/WASM (Critical Node):

  • Attack Vector: The process of porting C++ code to JavaScript/WASM can introduce new vulnerabilities. Memory management differences, incorrect assumptions during translation, or vulnerabilities in the WASM compilation toolchain itself could create security weaknesses.
  • Actionable Insight: Conduct thorough security reviews of the tesseract.js codebase and the WASM compilation process. Pay close attention to areas where C++ code interacts with JavaScript/WASM boundaries. Consider static analysis and code auditing tools to identify potential porting-related vulnerabilities.

• Insecure Configuration or Compilation of Tesseract WASM (Critical Node):

  • Attack Vector: An insecure WASM build process or misconfiguration could introduce vulnerabilities. For example, if the WASM build is not optimized or if debugging symbols are inadvertently included in production builds, it could increase the attack surface. Compromising the build infrastructure could also lead to the injection of malicious code into the WASM module.
  • Actionable Insight: Secure the WASM build process for tesseract.js. Ensure that the build environment is hardened, dependencies are managed securely, and the resulting WASM files are optimized and free of unnecessary debugging information. Implement integrity checks (e.g., checksums, SRI) to verify the integrity of downloaded WASM files.

Attack Tree Path: 4. Client-Side Specific Attacks related to tesseract.js Usage (High-Risk Path & Critical Node):

• Cross-Site Scripting (XSS) to Manipulate tesseract.js Input (High-Risk Path & Critical Node):

  • Attack Vector: If the web application using tesseract.js is vulnerable to Cross-Site Scripting (XSS), an attacker can inject malicious JavaScript code into the user's browser. This injected script can then manipulate the input provided to tesseract.js (e.g., by dynamically changing the image source or parameters), potentially feeding malicious images or triggering vulnerabilities in tesseract.js through the application's context.
  • Actionable Insight: Implement robust XSS prevention measures throughout the application. This includes input sanitization, output encoding, using Content Security Policy (CSP), and regularly auditing for XSS vulnerabilities.

• DOM Manipulation to Feed Malicious Images to tesseract.js (High-Risk Path & Critical Node):

  • Attack Vector: Even without traditional XSS, if the application handles DOM manipulation insecurely, an attacker might be able to modify the Document Object Model (DOM) to inject malicious image elements or alter existing ones that are then processed by tesseract.js. This could involve manipulating image src attributes or dynamically creating image elements with attacker-controlled URLs.
  • Actionable Insight: Secure the application against DOM-based XSS vulnerabilities. Carefully validate image sources and origins if images are loaded dynamically or if user input influences image loading. Avoid directly using user-provided data to manipulate DOM elements related to image processing.

• Man-in-the-Middle (MITM) Attack to Replace tesseract.js Library with Malicious Version (Critical Node):

  • Attack Vector: In a Man-in-the-Middle (MITM) attack, an attacker intercepts network traffic between the user's browser and the server. If the connection is not properly secured with HTTPS, or if Subresource Integrity (SRI) is not implemented, the attacker could replace the legitimate tesseract.js library file with a malicious version. This malicious library could then be used to execute arbitrary code within the user's browser, steal data, or perform other malicious actions.
  • Actionable Insight: Always serve the application and all its resources, including tesseract.js, over HTTPS to prevent MITM attacks. Implement Subresource Integrity (SRI) for tesseract.js and other external JavaScript libraries to ensure that the browser verifies the integrity of downloaded files and prevents malicious replacements.