attack-surface.md

Attack Surface Analysis for activemerchant/active_merchant

Attack Surface: Gateway API Vulnerabilities

• Description: Payment gateway APIs themselves might have security vulnerabilities (e.g., insecure endpoints, parameter manipulation, authentication flaws).
• Active Merchant Contribution: Active Merchant acts as an interface to these APIs. If a gateway API is vulnerable, applications using Active Merchant to interact with it are indirectly exposed.
• Example: A gateway API is vulnerable to parameter tampering, allowing modification of transaction amounts. Active Merchant, if used without proper validation of gateway interactions, could unknowingly facilitate sending manipulated requests.
• Impact: Financial fraud, unauthorized transactions, data breaches if API responses leak sensitive information due to the vulnerability.
• Risk Severity: High to Critical
• Mitigation Strategies:
  • Stay informed about security advisories from the payment gateway provider.
  • Use the latest versions of Active Merchant and gateway-specific gems, as updates may address known API compatibility issues or best practices.
  • Implement robust input validation and sanitization on your application side before sending data to Active Merchant and subsequently to the gateway.
  • Monitor gateway API communication for unusual patterns or errors that might indicate exploitation attempts.

Attack Surface: Man-in-the-Middle (MitM) Attacks on Gateway Communication

• Description: Attackers intercept communication between the application and the payment gateway to eavesdrop on or manipulate sensitive data in transit.
• Active Merchant Contribution: Active Merchant handles the communication with gateways over HTTPS. However, misconfigurations or vulnerabilities in the underlying SSL/TLS setup used by the application can still enable MitM attacks affecting Active Merchant's secure communication.
• Example: An attacker on a compromised network intercepts the HTTPS connection. Weak SSL/TLS configuration in the application's environment allows decryption of traffic, potentially exposing credit card details transmitted via Active Merchant.
• Impact: Data breaches, financial fraud, loss of customer trust.
• Risk Severity: High
• Mitigation Strategies:
  • Ensure proper SSL/TLS configuration on the application server and the network infrastructure. Use strong ciphers and up-to-date TLS protocols.
  • Enforce HTTPS for all communication with payment gateways within Active Merchant configuration.
  • Educate users about the risks of using untrusted networks (public Wi-Fi) for transactions.
  • Consider using certificate pinning (if feasible and applicable to the gateway communication) for enhanced security.

Attack Surface: API Key and Credential Exposure

• Description: Payment gateway API keys, merchant IDs, and other sensitive credentials required by Active Merchant are exposed, allowing unauthorized access to payment processing functionalities.
• Active Merchant Contribution: Active Merchant requires these credentials to be configured. Improper storage or handling of these credentials by developers directly leads to this attack surface.
• Example: API keys are hardcoded directly into the application code or stored in publicly accessible configuration files within the codebase repository. An attacker gaining access to the repository can steal these credentials and misuse Active Merchant through the application's gateway integration.
• Impact: Unauthorized transactions, financial fraud, account takeover, potential data breaches depending on the gateway's API capabilities.
• Risk Severity: Critical
• Mitigation Strategies:
  • Never hardcode API keys or sensitive credentials in the application code.
  • Use secure environment variables or dedicated secrets management systems (e.g., HashiCorp Vault, AWS Secrets Manager, Azure Key Vault) to store and access credentials.
  • Ensure configuration files containing credentials are not committed to version control systems.
  • Implement proper access control and permissions to restrict access to systems and files where credentials are stored.
  • Regularly rotate API keys and credentials as a security best practice.

Attack Surface: Sensitive Data Exposure in Logs

• Description: Sensitive payment information (credit card numbers, CVV, transaction details) is unintentionally logged in application logs, server logs, or debugging outputs.
• Active Merchant Contribution: While Active Merchant aims to handle sensitive data securely, improper logging practices in the application code that uses Active Merchant can lead to exposure of data processed by Active Merchant.
• Example: During debugging, verbose logging is enabled, and the application logs the entire request or response objects from Active Merchant, including sensitive card details. These logs are then accessible to unauthorized personnel or through log aggregation services with insufficient security.
• Impact: Data breaches, compliance violations (PCI DSS), reputational damage, identity theft.
• Risk Severity: High to Critical
• Mitigation Strategies:
  • Implement strict logging policies. Avoid logging sensitive data like full credit card numbers, CVV, or PINs. Log only necessary information for debugging and auditing.
  • Sanitize or redact sensitive data before logging. Mask credit card numbers (e.g., show only last 4 digits), remove CVV, etc.
  • Securely store and manage logs. Restrict access to log files and log aggregation systems to authorized personnel only.
  • Regularly review logs for accidental exposure of sensitive data and adjust logging practices accordingly.
  • Disable verbose or debug logging in production environments.

Attack Surface: Dependency Vulnerabilities

• Description: Vulnerabilities exist in the dependencies (gems and libraries) that Active Merchant relies upon.
• Active Merchant Contribution: Active Merchant has dependencies. Vulnerabilities in these dependencies directly impact the security of Active Merchant and applications using it.
• Example: A vulnerability is discovered in a Ruby gem used by Active Merchant for HTTP communication. An attacker could exploit this vulnerability through Active Merchant's functionality, potentially leading to remote code execution or denial of service.
• Impact: Various impacts depending on the vulnerability, ranging from denial of service to remote code execution, compromising applications using Active Merchant.
• Risk Severity: High
• Mitigation Strategies:
  • Regularly update Active Merchant and all its dependencies. Use tools like bundle audit or bundler-vuln to identify and patch known vulnerabilities in dependencies.
  • Monitor security advisories for Active Merchant and its dependencies.
  • Implement dependency scanning as part of the development and deployment pipeline.
  • Consider using dependency management tools that provide vulnerability scanning and alerting.

Attack Surface: Insecure Gem Installation and Management

• Description: The process of installing and managing Ruby gems, including Active Merchant, is compromised, leading to the installation of malicious or vulnerable versions.
• Active Merchant Contribution: If the gem installation process is insecure, a compromised version of Active Merchant itself could be installed, introducing vulnerabilities directly into the application's payment processing logic.
• Example: An attacker compromises a gem repository or performs a man-in-the-middle attack during gem installation to replace the legitimate Active Merchant gem with a malicious version containing backdoors or vulnerabilities.
• Impact: Complete compromise of the application, data breaches, malicious code execution, backdoors, specifically affecting payment processing functionality provided by Active Merchant.
• Risk Severity: Critical
• Mitigation Strategies:
  • Use trusted gem sources (e.g., rubygems.org). Avoid using unofficial or untrusted gem repositories.
  • Enable gem signing and verification. Verify the integrity and authenticity of gems before installation.
  • Use bundle install --frozen-lockfile in production to ensure consistent gem versions and prevent unexpected updates.
  • Implement a secure gem management workflow and restrict access to gem installation and management processes.