attack-tree.md

Attack Tree Analysis for thoughtbot/paperclip

Objective: Compromise Application Using Paperclip by Exploiting its Weaknesses

Attack Tree Visualization

Compromise Application Using Paperclip **[CRITICAL NODE]**
├───(OR)─ Exploit File Upload Vulnerabilities **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│   ├───(OR)─ Malicious File Upload & Execution **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│   │   ├───(AND)─ Bypass File Type Validation **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│   │   │   ├───(OR)─ Spoof File Extension **[HIGH-RISK PATH]**
│   │   │   │   └─── Change file extension to allowed type (e.g., .jpg, .png) **[HIGH-RISK PATH]**
│   │   │   ├───(OR)─ MIME Type Manipulation **[HIGH-RISK PATH]**
│   │   │   │   └─── Send crafted MIME type in HTTP header **[HIGH-RISK PATH]**
│   │   │   └───(OR)─ Exploiting Validation Logic Flaws **[HIGH-RISK PATH]**
│   │   │       └─── Identify and bypass weaknesses in custom validation logic **[HIGH-RISK PATH]**
│   │   └───(AND)─ Upload Malicious File **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│   │       ├───(OR)─ Web Shell Upload **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│   │       │   └─── Upload PHP, JSP, ASP, etc. web shell **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│   │       └───(OR)─ Exploitable File Format **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│   │           └─── Upload file format with known vulnerabilities (e.g., crafted image files exploiting image processing libraries) **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│   │   └───(AND)─ Achieve Code Execution **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│   │       └───(OR)─ Image Processing Vulnerabilities **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│   │           └─── Exploit vulnerabilities in image processing libraries (e.g., ImageMagick, MiniMagick) used by Paperclip during processing (e.g., ImageTragick) **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│
├───(OR)─ Exploit File Processing Vulnerabilities **[HIGH-RISK PATH]**
│   ├───(OR)─ Image Processing Library Vulnerabilities **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│   │   ├───(OR)─ Outdated Libraries **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│   │   │   └─── Exploit known vulnerabilities in outdated versions of image processing libraries (e.g., ImageMagick, MiniMagick) **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│   │   ├───(OR)─ Input-Based Exploits **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│   │   │   └─── Craft malicious input files (images, etc.) to trigger vulnerabilities in processing libraries (e.g., buffer overflows, command injection) **[HIGH-RISK PATH]** **[CRITICAL NODE]**
│
└───(OR)─ Exploit Configuration Vulnerabilities **[HIGH-RISK PATH]** **[CRITICAL NODE]**
    ├───(OR)─ Insecure Storage Backend Configuration **[HIGH-RISK PATH]** **[CRITICAL NODE]**
    │   ├───(OR)─ Publicly Accessible S3 Buckets **[HIGH-RISK PATH]** **[CRITICAL NODE]**
    │   │   └─── Misconfigure S3 buckets to be publicly readable/writable, exposing uploaded files and potentially allowing unauthorized uploads/modifications **[HIGH-RISK PATH]** **[CRITICAL NODE]**
    │   └───(OR)─ Exposed Storage Credentials **[HIGH-RISK PATH]** **[CRITICAL NODE]**
    │       └─── Hardcode or expose storage backend credentials, allowing attackers to directly access and manipulate storage **[HIGH-RISK PATH]** **[CRITICAL NODE]**
    ├───(OR)─ Insecure Paperclip Configuration **[HIGH-RISK PATH]** **[CRITICAL NODE]**
    │   └───(OR)─ Disabled or Weak Validations **[HIGH-RISK PATH]** **[CRITICAL NODE]**
    │       └─── Disable or use weak file type/size validations, making it easier to upload malicious files **[HIGH-RISK PATH]** **[CRITICAL NODE]**

Attack Tree Path: 1. Exploit File Upload Vulnerabilities [HIGH-RISK PATH] [CRITICAL NODE]:

• Attack Vectors:
  • Malicious File Upload & Execution [HIGH-RISK PATH] [CRITICAL NODE]:
    • Bypass File Type Validation [HIGH-RISK PATH] [CRITICAL NODE]:
      • Spoof File Extension [HIGH-RISK PATH]:
        • Attackers change the extension of a malicious file (e.g., a PHP web shell) to an allowed type like .jpg or .png to trick basic file extension checks.
      • MIME Type Manipulation [HIGH-RISK PATH]:
        • Attackers craft the HTTP request to send a manipulated Content-Type header, claiming the file is a safe MIME type (e.g., image/jpeg) while uploading a malicious file.
      • Exploiting Validation Logic Flaws [HIGH-RISK PATH]:
        • If custom validation logic is implemented, attackers analyze it for weaknesses and find ways to bypass it. This could involve exploiting regex flaws, logic errors, or race conditions in the validation process.
    • Upload Malicious File [HIGH-RISK PATH] [CRITICAL NODE]:
      • Web Shell Upload [HIGH-RISK PATH] [CRITICAL NODE]:
        • Attackers upload a web shell (e.g., PHP, JSP, ASP) disguised as a safe file type. If successful, they can execute arbitrary commands on the server through the web shell.
      • Exploitable File Format [HIGH-RISK PATH] [CRITICAL NODE]:
        • Attackers upload files in formats known to have vulnerabilities when processed by server-side libraries. For example, crafted image files can exploit vulnerabilities in image processing libraries like ImageMagick or MiniMagick.
    • Achieve Code Execution [HIGH-RISK PATH] [CRITICAL NODE]:
      • Image Processing Vulnerabilities [HIGH-RISK PATH] [CRITICAL NODE]:
        • Exploit vulnerabilities within image processing libraries (used by Paperclip for transformations and processing) to achieve code execution. A classic example is ImageTragick, where specially crafted image files could trigger command injection in ImageMagick.

Attack Tree Path: 2. Exploit File Processing Vulnerabilities [HIGH-RISK PATH]:

• Attack Vectors:
  • Image Processing Library Vulnerabilities [HIGH-RISK PATH] [CRITICAL NODE]:
    • Outdated Libraries [HIGH-RISK PATH] [CRITICAL NODE]:
      • Applications using Paperclip might rely on outdated versions of image processing libraries (like ImageMagick, MiniMagick). Attackers can exploit publicly known vulnerabilities in these outdated libraries to gain code execution or cause denial of service.
    • Input-Based Exploits [HIGH-RISK PATH] [CRITICAL NODE]:
      • Attackers craft malicious input files (specifically images in this context) designed to trigger vulnerabilities in the image processing libraries during processing. This can include buffer overflows, command injection, or other memory corruption issues.

Attack Tree Path: 3. Exploit Configuration Vulnerabilities [HIGH-RISK PATH] [CRITICAL NODE]:

• Attack Vectors:
  • Insecure Storage Backend Configuration [HIGH-RISK PATH] [CRITICAL NODE]:
    • Publicly Accessible S3 Buckets [HIGH-RISK PATH] [CRITICAL NODE]:
      • If Paperclip is configured to use cloud storage like AWS S3, misconfigurations can lead to S3 buckets being publicly readable or writable. This allows attackers to directly access, download, modify, or delete uploaded files, potentially leading to data breaches or data manipulation.
    • Exposed Storage Credentials [HIGH-RISK PATH] [CRITICAL NODE]:
      • Storage backend credentials (e.g., AWS access keys, database credentials) might be inadvertently hardcoded in the application code, configuration files, or exposed through other means. If attackers obtain these credentials, they gain direct access to the storage backend and can perform any operation, including data theft, modification, or deletion.
  • Insecure Paperclip Configuration [HIGH-RISK PATH] [CRITICAL NODE]:
    • Disabled or Weak Validations [HIGH-RISK PATH] [CRITICAL NODE]:
      • Developers might disable or weaken Paperclip's built-in file type or size validations, often for perceived performance gains or ease of use. This significantly increases the likelihood of successful malicious file uploads, as attackers face fewer obstacles in bypassing security checks.