attack-surface.md

Attack Surface Analysis for drupal/core

Attack Surface: Cross-Site Scripting (XSS) Vulnerabilities

• Description: Injection of malicious scripts into web pages viewed by other users.
• Core Contribution: Drupal core handles user-generated content, form rendering, and output generation. Insufficient input sanitization and output encoding within core or when using core APIs directly lead to XSS vulnerabilities.
• Example: A vulnerability in Drupal core's comment rendering logic allows injecting JavaScript into comments, affecting all users viewing the comment section.
• Impact: Account compromise, data theft, defacement, malware distribution, phishing attacks.
• Risk Severity: High to Critical (depending on the context and type of XSS).
• Mitigation Strategies:
  • Developers:
    • Strictly sanitize and validate all user inputs: Use Drupal's Form API and its built-in validation and sanitization mechanisms.
    • Properly encode output: Utilize Twig's auto-escaping features and Drupal's \Drupal\Component\Utility\Html::escape() or \Drupal\Component\Utility\Xss::filterAdmin() functions when rendering user-generated content within core templates and code.
    • Implement Content Security Policy (CSP): Configure CSP headers to restrict resource loading, mitigating XSS impact.
  • Users/Administrators:
    • Keep Drupal core updated: Security updates patch XSS vulnerabilities in core.

Attack Surface: SQL Injection Vulnerabilities

• Description: Exploitation of vulnerabilities in database queries to inject malicious SQL code, allowing attackers to manipulate the database.
• Core Contribution: Drupal core's database abstraction layer and query building tools, if flawed or misused within core, can introduce SQL injection points.
• Example: A vulnerability in Drupal core's node listing functionality allows injecting SQL through crafted URL parameters, leading to unauthorized data access.
• Impact: Data breach, data manipulation, complete database compromise, denial of service.
• Risk Severity: Critical.
• Mitigation Strategies:
  • Developers:
    • Always use Drupal's database abstraction layer (Database API): Utilize parameterized queries and prepared statements provided by Drupal's db_query() and related functions in core code.
    • Avoid direct string concatenation in queries: Never directly embed user input into SQL query strings within core.
  • Users/Administrators:
    • Keep Drupal core updated: Security updates patch SQL injection vulnerabilities in core.

Attack Surface: Authentication Bypass Vulnerabilities

• Description: Circumventing Drupal's authentication mechanisms to gain unauthorized access without valid credentials.
• Core Contribution: Drupal core manages user authentication, session handling, and password management. Vulnerabilities in these core systems directly lead to authentication bypass.
• Example: A flaw in Drupal core's login form processing allows bypassing authentication checks, granting unauthorized access to the site.
• Impact: Unauthorized access to sensitive data, account compromise, administrative takeover.
• Risk Severity: Critical.
• Mitigation Strategies:
  • Developers:
    • Follow secure authentication practices: Implement robust password hashing, secure session management within core.
    • Thoroughly test authentication workflows: Ensure all authentication paths are secure and resistant to bypass attempts in core.
  • Users/Administrators:
    • Keep Drupal core updated: Security updates patch authentication bypass vulnerabilities in core.

Attack Surface: Access Control Bypass Vulnerabilities

• Description: Circumventing Drupal's permission system to access resources or functionalities without proper authorization.
• Core Contribution: Drupal core implements a role-based access control (RBAC) system. Vulnerabilities in core's permission checking logic or implementation lead to access control bypass.
• Example: A vulnerability in Drupal core's node access system allows users to view or edit content they should not have access to, bypassing core permission checks.
• Impact: Unauthorized access to sensitive data, privilege escalation, data manipulation.
• Risk Severity: High to Critical (depending on the sensitivity of the bypassed access).
• Mitigation Strategies:
  • Developers:
    • Implement robust access control checks: Use Drupal's Permission API and Node Access API correctly to enforce access restrictions within core.
    • Thoroughly test access control logic: Ensure permissions are correctly enforced across all functionalities in core.
  • Users/Administrators:
    • Keep Drupal core updated: Security updates patch access control bypass vulnerabilities in core.

Attack Surface: Password Reset Vulnerabilities

• Description: Exploiting weaknesses in the password reset process to gain unauthorized access to user accounts.
• Core Contribution: Drupal core provides the password reset functionality. Flaws in core's password reset mechanism can be exploited.
• Example: A vulnerability in Drupal core's password reset token generation allows attackers to predict or brute-force tokens, enabling password resets for arbitrary accounts.
• Impact: Account compromise, unauthorized access.
• Risk Severity: High.
• Mitigation Strategies:
  • Developers:
    • Implement secure password reset mechanisms: Use strong, unpredictable tokens, secure token storage, and proper validation within core.
    • Implement rate limiting on password reset requests: Prevent brute-force attacks.
  • Users/Administrators:
    • Keep Drupal core updated: Security updates patch password reset vulnerabilities in core.

Attack Surface: Remote Code Execution (RCE) via File Upload Vulnerabilities (Potentially High/Critical depending on context)

• Description: Uploading malicious files that can be executed by the server, leading to complete system compromise.
• Core Contribution: Drupal core handles file uploads and management. Vulnerabilities in core's file handling or validation can allow uploading and executing malicious files. While direct RCE in core file upload is less common now, misconfigurations or vulnerabilities in image processing libraries used by core could lead to RCE.
• Example: A vulnerability in Drupal core's image handling allows uploading a specially crafted image file that, when processed by the server, executes arbitrary code.
• Impact: Complete server compromise, data breach, website defacement, malware distribution.
• Risk Severity: High to Critical (depending on the ease of exploitation and impact).
• Mitigation Strategies:
  • Developers:
    • Strictly validate file uploads: Check file types, sizes, and contents to prevent uploading malicious files within core's file handling.
    • Sanitize filenames: Prevent directory traversal or command injection through filenames.
    • Store uploaded files outside the web root: Prevent direct execution of uploaded files.
    • Keep image processing libraries updated: Vulnerabilities in these libraries can be exploited via malicious images.
  • Users/Administrators:
    • Keep Drupal core and modules updated: Security updates patch file upload and processing vulnerabilities.
    • Restrict file upload permissions: Limit who can upload files and what file types are allowed.