attack-surface.md

Attack Surface Analysis for drapergem/draper

Attack Surface: Unintended Data Exposure

• Description: Decorators, designed for presentation, might inadvertently expose sensitive data due to insufficient filtering or authorization checks within their logic, leading to unauthorized access.
• Draper Contribution: Draper's core purpose is to encapsulate presentation logic within decorators. If developers rely solely on decorators for data presentation without implementing robust security checks within the decorators themselves, sensitive data can be exposed in unintended contexts. Draper encourages this separation of concerns, which, if not handled carefully, can lead to this exposure.
• Example: A UserDecorator might be created to display user details. If this decorator fetches and displays a social_security_number attribute without context-aware checks, and is used in a view accessible to unauthorized users (e.g., due to developer oversight in view selection or routing), the SSN could be exposed.
• Impact: Critical confidentiality breach, severe privacy violation, potential for identity theft, legal and regulatory repercussions.
• Risk Severity: Critical
• Mitigation Strategies:
  • Implement Context-Aware Authorization in Decorators: Within decorators, explicitly check user roles, permissions, or context parameters before rendering sensitive data. Do not assume the view context is inherently secure.
  • Principle of Least Privilege in Decorators: Decorators should only access and present the minimum data necessary for the intended view context. Avoid fetching and making available sensitive attributes if they are not strictly required for presentation.
  • Dedicated Decorators for Security Contexts: Create specific decorators tailored to different security contexts (e.g., AdminUserDecorator, PublicUserDecorator). This enforces explicit control over what data is presented in each context and reduces the risk of accidental over-exposure.

Attack Surface: Logic Errors Leading to Information Disclosure

• Description: Flaws in the conditional logic within decorators, intended to tailor presentation based on roles or conditions, can inadvertently bypass security measures and disclose sensitive information to unauthorized users.
• Draper Contribution: Decorators often contain conditional logic to dynamically adjust the presentation. Complex or poorly tested conditional statements within decorators, especially those related to authorization or data filtering, can introduce vulnerabilities. Draper's flexibility in allowing logic within decorators increases the potential for such errors if not carefully managed.
• Example: A decorator conditionally displays a user's salary information if they are marked as "privileged." A flawed conditional statement (e.g., incorrect boolean logic or missing role check) might incorrectly evaluate to true for unauthorized users, leading to the display of salary data when it should be hidden.
• Impact: High confidentiality breach, significant information disclosure, potential for financial fraud or internal misuse of information.
• Risk Severity: High
• Mitigation Strategies:
  • Simplify Decorator Logic: Keep conditional logic within decorators as simple and straightforward as possible. Complex logic should ideally be handled in model or service layers, with decorators focusing purely on presentation based on clear, pre-determined conditions.
  • Rigorous Unit Testing of Decorator Logic: Thoroughly unit test all conditional branches and data handling within decorators. Focus on testing edge cases and different user roles/permissions to ensure logic behaves as expected under all circumstances.
  • Code Reviews Focused on Security Logic: Conduct dedicated code reviews specifically examining the security-related logic within decorators, paying close attention to conditional statements, authorization checks, and data filtering mechanisms.

Attack Surface: Abuse of Vulnerable Helper Methods in Decorators (Indirectly facilitated by Draper)

• Description: While the vulnerability resides in helper methods, Draper allows decorators to utilize these helpers. If vulnerable helpers (e.g., susceptible to XSS) are used within decorators to format or present data, decorators can become a pathway to exploit these helper vulnerabilities, especially if user-controlled data is processed.
• Draper Contribution: Draper's design allows decorators to seamlessly integrate with and utilize view helpers. This tight integration, while convenient, means that vulnerabilities in helpers can be easily exploited through decorators if developers are not cautious about data sanitization both in helpers and when calling helpers from decorators. Draper itself doesn't introduce the helper vulnerability, but it provides a readily available mechanism for decorators to use them, potentially amplifying the risk if helpers are insecure.
• Example: A helper method sanitize_and_format(text) is intended to sanitize input but contains an XSS vulnerability. A decorator uses this helper to display user-generated content. If the decorator passes unsanitized user input to this flawed helper, it effectively introduces an XSS vulnerability through the decorator's presentation layer, even though the root cause is in the helper.
• Impact: High risk of Cross-Site Scripting (XSS) attacks, leading to potential account compromise, session hijacking, data theft, and malware injection.
• Risk Severity: High
• Mitigation Strategies:
  • Secure and Audit View Helper Methods: Prioritize securing all view helper methods. Regularly audit and test helpers for common vulnerabilities like XSS, SQL injection, and command injection. Ensure helpers are robustly sanitized and validated.
  • Sanitize Inputs Before Helper Calls in Decorators: Even if helpers are assumed to be secure, practice defense-in-depth. Sanitize user inputs before passing them to helper methods within decorators. This adds an extra layer of protection against potential helper vulnerabilities.
  • Minimize Complex Logic in Helpers: Keep helper methods focused on simple, well-defined tasks. Avoid complex logic or data manipulation within helpers, as this increases the chance of introducing vulnerabilities.