attack-surface.md

Attack Surface Analysis for norman/friendly_id

Attack Surface: Slug Predictability and Brute-Force Resource Access

• Description: Predictable slug generation allows attackers to guess valid slugs and gain unauthorized access to resources.
• How Friendly_id Contributes: friendly_id's slug generation, if using simple or sequential patterns, creates predictable slugs. Default configurations or basic slug strategies can exacerbate this.
• Example: Sequential slugs like resource-1, resource-2 enable attackers to easily enumerate and access resources they shouldn't.
• Impact: High. Unauthorized access to sensitive resources and information disclosure.
• Risk Severity: High.
• Mitigation Strategies:
  • Utilize UUIDs or cryptographically random strings for slug bases to ensure unpredictability.
  • Enforce robust authorization checks at the application level, independent of slug-based access.
  • Implement rate limiting to thwart brute-force slug guessing attempts.

Attack Surface: Slug Collision Vulnerabilities leading to Denial of Service (DoS)

• Description: Exploiting predictable or inefficient slug collision handling in friendly_id can lead to Denial of Service.
• How Friendly_id Contributes: friendly_id's collision resolution (e.g., appending numbers) can become computationally expensive if attackers intentionally trigger numerous collisions, especially with large datasets and complex history/redirect configurations.
• Example: An attacker creates many resources with titles designed to collide, forcing friendly_id into resource-intensive collision resolution, potentially overloading the server.
• Impact: High. Denial of Service, application unavailability.
• Risk Severity: High.
• Mitigation Strategies:
  • Employ longer, more unique slug bases to minimize collision probability.
  • Thoroughly test and optimize collision handling performance, especially under high load and collision scenarios.
  • Implement caching for slug lookups to reduce database load during collision resolution.
  • Monitor for and alert on excessive collision events, which may indicate malicious activity.

Attack Surface: Information Disclosure through Sensitive Data in Slugs

• Description: Exposure of sensitive information in URLs due to its inclusion in generated slugs.
• How Friendly_id Contributes: friendly_id generates slugs from model attributes. Using attributes containing sensitive data directly in slug generation makes this data publicly visible in URLs.
• Example: Including user IDs or internal identifiers in slugs exposes these details in URLs, potentially aiding attackers in reconnaissance or direct access attempts.
• Impact: High. Disclosure of sensitive user or system information.
• Risk Severity: High.
• Mitigation Strategies:
  • Avoid using sensitive attributes for slug generation.
  • Sanitize or redact sensitive data from slug bases before slug creation.
  • Regularly review slug generation logic to prevent unintended sensitive data exposure.

Attack Surface: Open Redirect Vulnerabilities via Unvalidated Slug History Redirects

• Description: Abuse of friendly_id's slug history and redirect feature to create open redirect vulnerabilities, leading to phishing or malware distribution.
• How Friendly_id Contributes: friendly_id's automatic redirects from old slugs can be exploited if the application doesn't validate redirect targets, allowing attackers to inject external URLs into old slugs.
• Example: An attacker manipulates an old slug to point to a malicious external site. Users accessing the old slug are unknowingly redirected to the attacker's site.
• Impact: High. Open redirect, phishing attacks, malware distribution, significant reputational damage.
• Risk Severity: High.
• Mitigation Strategies:
  • Implement strict validation of redirect targets. Only allow redirects to internal application paths or a whitelist of trusted domains.
  • Consider disabling automatic redirects if the risk is deemed too high and redirect functionality is not critical.
  • If redirects are necessary, implement user warnings before redirecting to external domains.

Attack Surface: Business Logic Bypasses due to Slug Uniqueness or Modification Issues

• Description: Circumvention of business logic and access controls due to flawed assumptions about slug uniqueness or mutability when using friendly_id.
• How Friendly_id Contributes: Misconfigurations or misunderstandings of friendly_id's uniqueness enforcement or slug modification behavior can lead to vulnerabilities if business logic relies on specific slug properties.
• Example: Business logic assumes slug immutability for access control. If slugs can be unexpectedly changed (e.g., through title edits), attackers might bypass these controls by manipulating slugs. Or, lack of strict uniqueness enforcement could lead to accessing incorrect resources if business logic relies on unique slug-to-resource mapping.
• Impact: High. Bypasses of critical business logic, potential for unauthorized actions and data manipulation.
• Risk Severity: High.
• Mitigation Strategies:
  • Clearly define and rigorously enforce slug uniqueness and mutability requirements in both application code and friendly_id configuration.
  • Use database-level unique constraints in addition to friendly_id validations for slug uniqueness.
  • Thoroughly test business logic that depends on slug properties to ensure it behaves as expected under various slug manipulation scenarios.
  • Consider making slugs truly immutable after creation if business logic relies on this property for security.