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Okay, let's create a design document for the Drupal core project, keeping in mind its purpose and potential security considerations.

BUSINESS POSTURE

Drupal is a widely-used, open-source Content Management System (CMS). It powers a significant portion of the web, ranging from personal blogs to large enterprise and government websites. Therefore, the business posture centers around maintaining trust, ensuring stability, and fostering a vibrant community.

Priorities and Goals:

  • Provide a flexible and extensible platform for building websites and applications.
  • Maintain a high level of security and stability to protect user data and ensure website availability.
  • Foster a strong and active community of developers and contributors.
  • Ensure backwards compatibility and a smooth upgrade path for existing installations.
  • Provide comprehensive documentation and support resources.
  • Adapt to evolving web standards and technologies.

Business Risks:

  • Reputational damage due to security vulnerabilities or data breaches.
  • Loss of user trust and adoption due to instability or poor performance.
  • Decline in community participation, leading to slower development and fewer contributions.
  • Inability to keep up with evolving web standards, leading to obsolescence.
  • Legal and compliance issues related to data privacy and security.
  • Competition from other CMS platforms.

SECURITY POSTURE

Drupal has a well-established security team and a history of addressing vulnerabilities promptly. However, given its widespread use and the complexity of web applications, ongoing vigilance is crucial.

Existing Security Controls:

  • security control: A dedicated security team that reviews code, responds to vulnerability reports, and releases security advisories. (Documented on Drupal.org security pages).
  • security control: Regular security releases and updates to address known vulnerabilities. (Documented on Drupal.org).
  • security control: A well-defined process for reporting and handling security vulnerabilities. (Documented on Drupal.org).
  • security control: Coding standards and best practices that promote secure development. (Documented in Drupal's coding standards documentation).
  • security control: Input validation and output encoding to mitigate cross-site scripting (XSS) and other injection attacks. (Implemented throughout the codebase).
  • security control: Access control mechanisms to restrict access to sensitive data and functionality. (Implemented in the core user and permission system).
  • security control: Password hashing using strong, one-way algorithms (bcrypt). (Implemented in the user authentication system).
  • security control: Protection against Cross-Site Request Forgery (CSRF) attacks using tokens. (Implemented in the form API).
  • security control: Database abstraction layer to prevent SQL injection vulnerabilities. (Implemented in the database API).
  • security control: Support for HTTPS and other security-related HTTP headers. (Configurable in site settings).
  • security control: File system permissions management to restrict access to sensitive files. (Configurable in site settings and documented).
  • security control: A robust update system to ensure that sites can be easily updated to the latest secure version. (Implemented in the update manager).
  • security control: Session management that uses secure cookies and mitigates session hijacking risks. (Implemented in the session handling system).

Accepted Risks:

  • accepted risk: The inherent risk of zero-day vulnerabilities in any complex software system.
  • accepted risk: The risk of misconfiguration by site administrators, leading to security vulnerabilities.
  • accepted risk: The risk of vulnerabilities in contributed modules or themes that are not maintained by the core Drupal security team.
  • accepted risk: Reliance on third-party libraries and dependencies, which may have their own vulnerabilities.

Recommended Security Controls:

  • Implement a Content Security Policy (CSP) to mitigate XSS and other code injection attacks.
  • Enable HTTP Strict Transport Security (HSTS) to enforce HTTPS connections.
  • Regularly audit and review contributed modules and themes for security vulnerabilities.
  • Implement a robust web application firewall (WAF) to protect against common web attacks.
  • Consider implementing multi-factor authentication (MFA) for administrative users.

Security Requirements:

  • Authentication:

    • All users must be authenticated before accessing restricted resources.
    • Strong password policies must be enforced.
    • Support for multi-factor authentication should be considered.
    • Session management must be secure and prevent session hijacking.

  • Authorization:

    • A granular permission system must control access to different functionalities and content.
    • The principle of least privilege should be applied.
    • Access control decisions must be logged and auditable.

  • Input Validation:

    • All user input must be validated and sanitized to prevent injection attacks (XSS, SQLi, etc.).
    • Input validation should be performed on both the client-side and server-side.
    • A whitelist approach to input validation should be preferred over a blacklist approach.

  • Cryptography:

    • Sensitive data, such as passwords, must be stored using strong, one-way hashing algorithms.
    • All communication between the client and server should be encrypted using HTTPS.
    • Cryptographic keys must be managed securely.

DESIGN

C4 CONTEXT

graph LR
    User(("User"))
    DrupalCore[("Drupal Core")]
    Database[(("Database"))]
    WebServer(("Web Server"))
    ThirdPartyServices(("Third-Party Services"))
    ContribModules(("Contributed Modules"))
    CustomModules(("Custom Modules"))
    Themes(("Themes"))

    User -- "Uses" --> DrupalCore
    DrupalCore -- "Reads/Writes" --> Database
    DrupalCore -- "Serves content" --> WebServer
    WebServer -- "HTTP/HTTPS" --> User
    DrupalCore -- "Integrates with" --> ThirdPartyServices
    DrupalCore -- "Extends" --> ContribModules
    DrupalCore -- "Extends" --> CustomModules
    DrupalCore -- "Uses" --> Themes
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Element Descriptions:

  • Element:

    • Name: User
    • Type: Person
    • Description: A person interacting with the Drupal website through a web browser.
    • Responsibilities: Browsing content, submitting forms, interacting with the website's features.
    • Security controls: Browser security settings, HTTPS connection.

  • Element:

    • Name: Drupal Core
    • Type: Software System
    • Description: The core Drupal CMS software.
    • Responsibilities: Managing content, users, permissions, modules, themes, and overall website functionality.
    • Security controls: Input validation, output encoding, access control, password hashing, CSRF protection, database abstraction, session management.

  • Element:

    • Name: Database
    • Type: Database
    • Description: The database used to store Drupal's content, users, configuration, and other data.
    • Responsibilities: Storing and retrieving data.
    • Security controls: Database user access control, encryption at rest (if applicable), regular backups.

  • Element:

    • Name: Web Server
    • Type: Software System
    • Description: The web server (e.g., Apache, Nginx) that serves Drupal's content to users.
    • Responsibilities: Handling HTTP requests, serving static files, and routing requests to Drupal.
    • Security controls: Web server configuration hardening, HTTPS configuration, WAF (if applicable).

  • Element:

    • Name: Third-Party Services
    • Type: Software System
    • Description: External services that Drupal may integrate with (e.g., payment gateways, social media APIs, analytics services).
    • Responsibilities: Varies depending on the service.
    • Security controls: Secure API communication, authentication and authorization with the third-party service.

  • Element:

    • Name: Contributed Modules
    • Type: Software System
    • Description: Modules developed by the Drupal community to extend Drupal's functionality.
    • Responsibilities: Varies depending on the module.
    • Security controls: Adherence to Drupal coding standards, security reviews (ideally), regular updates.

  • Element:

    • Name: Custom Modules
    • Type: Software System
    • Description: Modules developed specifically for a particular Drupal site.
    • Responsibilities: Varies depending on the module.
    • Security controls: Adherence to Drupal coding standards, security reviews, regular updates.

  • Element:

    • Name: Themes
    • Type: Software System
    • Description: Templates and stylesheets that control the visual appearance of the Drupal site.
    • Responsibilities: Presenting content to the user.
    • Security controls: Secure coding practices to prevent XSS and other vulnerabilities.

C4 CONTAINER

graph LR
    User(("User"))
    WebServer(("Web Server"))
    PHP(("PHP Interpreter"))
    Database[(("Database"))]
    Cache[(("Cache System"))]
    Files(("File System"))]

    User -- "HTTPS" --> WebServer
    WebServer -- "FastCGI/PHP-FPM" --> PHP
    PHP -- "Queries/Updates" --> Database
    PHP -- "Reads/Writes" --> Cache
    PHP -- "Reads/Writes" --> Files
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Element Descriptions:

  • Element:

    • Name: User
    • Type: Person
    • Description: A person interacting with the Drupal website.
    • Responsibilities: Browsing, submitting forms, interacting with the site.
    • Security controls: Browser security, HTTPS.

  • Element:

    • Name: Web Server
    • Type: Container (Software)
    • Description: Handles HTTP requests (e.g., Apache, Nginx).
    • Responsibilities: Serving static content, routing requests to PHP.
    • Security controls: HTTPS configuration, WAF, access controls.

  • Element:

    • Name: PHP Interpreter
    • Type: Container (Runtime Environment)
    • Description: Executes Drupal's PHP code.
    • Responsibilities: Processing requests, interacting with the database, cache, and file system.
    • Security controls: Secure PHP configuration, input validation, output encoding.

  • Element:

    • Name: Database
    • Type: Container (Database)
    • Description: Stores Drupal's data (e.g., MySQL, PostgreSQL).
    • Responsibilities: Data storage and retrieval.
    • Security controls: Database access control, encryption at rest.

  • Element:

    • Name: Cache System
    • Type: Container (Cache)
    • Description: Caches frequently accessed data to improve performance (e.g., Memcached, Redis).
    • Responsibilities: Storing and retrieving cached data.
    • Security controls: Access control to the cache system.

  • Element:

    • Name: File System
    • Type: Container (File System)
    • Description: Stores files uploaded by users and managed by Drupal.
    • Responsibilities: Storing and serving files.
    • Security controls: File system permissions, secure file uploads.

DEPLOYMENT

Possible Deployment Solutions:

  1. Traditional LAMP/LEMP stack on a single server.
  2. Cloud-based deployment using managed services (e.g., AWS, Azure, Google Cloud).
  3. Containerized deployment using Docker and Kubernetes.
  4. Platform-as-a-Service (PaaS) solutions (e.g., Acquia, Pantheon).

Chosen Solution (for detailed description): Cloud-based deployment using managed services (AWS).

graph LR
    Internet(("Internet"))
    LoadBalancer(("Load Balancer"))
    WebServer1(("Web Server (EC2)"))
    WebServer2(("Web Server (EC2)"))
    RDS[(("RDS (MySQL)"))]
    EFS(("EFS"))
    ElastiCache(("ElastiCache (Redis)"))

    Internet -- "HTTPS" --> LoadBalancer
    LoadBalancer -- "HTTPS" --> WebServer1
    LoadBalancer -- "HTTPS" --> WebServer2
    WebServer1 -- "SQL" --> RDS
    WebServer2 -- "SQL" --> RDS
    WebServer1 -- "NFS" --> EFS
    WebServer2 -- "NFS" --> EFS
    WebServer1 -- "" --> ElastiCache
    WebServer2 -- "" --> ElastiCache
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Element Descriptions:

  • Element:

    • Name: Internet
    • Type: Network
    • Description: The global network.
    • Responsibilities: Routing traffic to the load balancer.
    • Security controls: Standard internet security protocols.

  • Element:

    • Name: Load Balancer
    • Type: Infrastructure Node (AWS ELB)
    • Description: Distributes traffic across multiple web servers.
    • Responsibilities: Load balancing, SSL termination.
    • Security controls: AWS security groups, HTTPS configuration.

  • Element:

    • Name: Web Server 1 & 2
    • Type: Infrastructure Node (AWS EC2)
    • Description: Instances running the web server (e.g., Apache, Nginx) and PHP.
    • Responsibilities: Serving Drupal content.
    • Security controls: AWS security groups, OS hardening, web server configuration.

  • Element:

    • Name: RDS
    • Type: Infrastructure Node (AWS RDS)
    • Description: Managed database service (MySQL).
    • Responsibilities: Data storage and retrieval.
    • Security controls: AWS security groups, database user access control, encryption at rest.

  • Element:

    • Name: EFS
    • Type: Infrastructure Node (AWS EFS)
    • Description: Shared file system for uploaded files.
    • Responsibilities: File storage and sharing between web servers.
    • Security controls: AWS security groups, NFS access control.

  • Element:

    • Name: ElastiCache
    • Type: Infrastructure Node (AWS ElastiCache)
    • Description: Managed caching service (Redis).
    • Responsibilities: Caching frequently accessed data.
    • Security controls: AWS security groups, access control to the cache service.

BUILD

Drupal core doesn't have a traditional "build" process in the same way as compiled languages. However, there's a process for packaging releases and managing dependencies. This is largely handled by the Drupal community and infrastructure.

graph LR
    Developer(("Developer"))
    Git(("Git Repository (drupal.org)"))
    CI(("CI System (drupal.org)"))
    Packagist(("Packagist"))
    Composer(("Composer"))
    DrupalRelease(("Drupal Release"))

    Developer -- "Commits code" --> Git
    Git -- "Triggers build" --> CI
    CI -- "Runs tests" --> CI
    CI -- "Creates package" --> Packagist
    Composer -- "Downloads dependencies" --> Packagist
    Composer -- "Installs Drupal" --> DrupalRelease
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Security Controls in the Build Process:

  • Code Review: All code changes are reviewed by other developers before being merged.
  • Automated Testing: Drupal has an extensive suite of automated tests (unit, functional, integration) that are run on every code change.
  • Static Analysis: Static analysis tools are used to identify potential security vulnerabilities and coding standard violations.
  • Dependency Management: Composer is used to manage dependencies and ensure that only trusted and up-to-date packages are used.
  • Release Management: The Drupal security team manages the release process and ensures that security releases are created and distributed promptly.
  • Infrastructure Security: Drupal.org's infrastructure is secured to prevent unauthorized access and modification of the codebase.

RISK ASSESSMENT

Critical Business Processes:

  • Content delivery and presentation.
  • User authentication and authorization.
  • Content creation and management.
  • Website administration and configuration.
  • Extensibility via modules and themes.

Data Sensitivity:

  • Personally Identifiable Information (PII): Usernames, email addresses, IP addresses, and potentially other personal data stored in user profiles or submitted through forms. (High Sensitivity)
  • Content Data: The content of the website, which may include sensitive or confidential information depending on the nature of the site. (Variable Sensitivity - from Low to High)
  • Configuration Data: Website configuration settings, which may contain sensitive information such as database credentials or API keys. (High Sensitivity)
  • Session Data: User session data, which can be used to hijack user sessions if compromised. (High Sensitivity)
  • Logs: System and application logs, which may contain sensitive information about user activity or system errors. (Medium Sensitivity)

QUESTIONS & ASSUMPTIONS

Questions:

  • What specific third-party services are commonly integrated with Drupal installations? This will help in assessing the risks associated with those integrations.
  • What is the typical level of technical expertise of Drupal site administrators? This will influence the recommendations for security configuration and best practices.
  • Are there any specific compliance requirements (e.g., GDPR, HIPAA) that need to be considered for typical Drupal installations?

Assumptions:

  • BUSINESS POSTURE: We assume a mid-sized organization or project with a moderate risk appetite. They value security but also need to balance it with usability and functionality.
  • SECURITY POSTURE: We assume that the Drupal core is kept up-to-date with the latest security releases. We also assume that site administrators have a basic understanding of security best practices.
  • DESIGN: We assume a standard Drupal installation with common modules and themes. We also assume that the deployment environment is reasonably secure.