attack-surface.md

Attack Surface Analysis for paper-trail-gem/paper_trail

Attack Surface: Exposure of Sensitive Data in Version History

• Description: Sensitive data tracked by PaperTrail and stored in the versions table can be exposed to unauthorized users if access controls are insufficient. This is a direct consequence of PaperTrail's functionality of recording changes.
• PaperTrail Contribution: PaperTrail's core function is to track changes, and by default, it can track sensitive attributes if not configured carefully. This leads to sensitive data being persisted in the version history.
• Example: A user's password reset token is temporarily stored in a user model attribute and tracked by PaperTrail. If version history access is not restricted, an attacker could potentially retrieve this token from the versions table even after it's been cleared from the current user record, potentially leading to account takeover.
• Impact: Confidentiality breach, PII exposure, potential identity theft, account takeover, regulatory compliance violations.
• Risk Severity: Critical
• Mitigation Strategies:
  • Attribute Filtering (Critical): Utilize PaperTrail's ignore or only options in model configurations to explicitly exclude sensitive attributes from being tracked. This is the most direct way to prevent sensitive data from entering version history.
  • Strict Access Control (High): Implement robust authorization mechanisms to severely restrict access to version history features and the versions table. Access should be limited to only essential personnel and audited regularly.
  • Data Sanitization Pre-Versioning (High): Before PaperTrail creates versions, implement application-level logic to sanitize or redact sensitive data within the tracked attributes. This ensures sensitive information is never persisted in version history.
  • Data Encryption at Rest (High): Encrypt the database at rest to protect sensitive data within the versions table from unauthorized physical access or database breaches.

Attack Surface: Deserialization Vulnerabilities (If Custom Serializers are Used)

• Description: If developers implement custom serializers for PaperTrail and use insecure deserialization methods, it can introduce Remote Code Execution (RCE) vulnerabilities. This is a direct risk if PaperTrail's extensibility is misused.
• PaperTrail Contribution: PaperTrail allows for the use of custom serializers to handle data serialization. If these custom serializers employ unsafe deserialization practices, they become a direct attack vector within the PaperTrail ecosystem.
• Example: A custom serializer uses Marshal.load to deserialize data for versioned attributes. An attacker, through some vulnerability (even indirect), manages to inject malicious serialized data into the versions table. When this version is accessed and deserialized, it executes arbitrary code on the server.
• Impact: Remote Code Execution (RCE), complete server compromise, data breach, denial of service, significant business disruption.
• Risk Severity: Critical
• Mitigation Strategies:
  • Avoid Custom Serializers (Critical): Prefer PaperTrail's default serializers whenever possible. They are designed to be secure. Only use custom serializers if absolutely necessary and after thorough security review.
  • Secure Deserialization Practices (Critical): If custom serializers are unavoidable, absolutely avoid unsafe deserialization methods like Marshal.load on potentially untrusted data. Use safer formats like JSON and secure deserialization libraries.
  • Input Validation for Serializers (High): If custom serializers handle any form of external input or data that could be influenced by attackers, rigorously validate and sanitize this input before deserialization.
  • Code Review and Security Audit (High): Mandatory security code reviews and audits of any custom serializer implementations are crucial to identify and eliminate deserialization vulnerabilities before deployment.

Attack Surface: Configuration Mismanagement Leading to Sensitive Data Exposure

• Description: Incorrect or insecure configuration of PaperTrail, particularly regarding tracked attributes, can lead to the unintentional logging of sensitive data in version history, increasing the attack surface. This is a direct consequence of how PaperTrail is set up.
• PaperTrail Contribution: PaperTrail's configuration directly dictates what data is tracked. Default or poorly considered configurations can easily result in sensitive information being logged without proper awareness of the security implications.
• Example: Developers fail to use ignore or only options and PaperTrail defaults to tracking all attributes of user models, including fields intended for temporary storage of sensitive information during password reset or two-factor authentication processes. This sensitive data ends up permanently in the version history.
• Impact: Confidentiality breach, PII exposure, potential identity theft, regulatory compliance violations.
• Risk Severity: High
• Mitigation Strategies:
  • Principle of Least Privilege in Configuration (High): Proactively configure PaperTrail to track only the absolutely necessary attributes. Defaulting to tracking everything is insecure. Explicitly define what to track using only or ignore lists.
  • Regular Configuration Audits (High): Establish a process for regularly auditing PaperTrail configurations to ensure they remain secure and aligned with data minimization principles. Review tracked attributes whenever models are modified or new sensitive data is introduced.
  • Secure Configuration Management (High): Manage PaperTrail configurations as part of the application's overall secure configuration management strategy. Avoid hardcoding sensitive configuration details and use environment variables or secure configuration stores.