Attack Surface: 1. Unintended Side Effects in Candidate Code
- Description: The candidate (new) code path, even if intended for observation, contains a vulnerability that causes unintended state changes or external interactions.
- Scientist Contribution: Scientist executes the candidate code path alongside the control path, making any vulnerability in the candidate code directly exploitable in a production environment. This is the fundamental and most critical risk of using Scientist.
- Example: A candidate code path intended to read user data has a SQL injection vulnerability. Scientist executes this vulnerable code, allowing an attacker to modify or delete data.
- Impact: Data corruption, data loss, unauthorized access, system compromise.
- Risk Severity: Critical
- Mitigation Strategies:
- Rigorous Code Review: Perform extremely thorough code reviews of all candidate code, focusing on security vulnerabilities. This is the most important mitigation.
- Input Validation & Output Encoding: Implement strict input validation and output encoding in the candidate code, even if it's believed to be read-only.
- Sandboxing/Isolation: If possible, execute the candidate code in a sandboxed environment with limited privileges. Consider database transactions that are always rolled back.
- Principle of Least Privilege: Ensure the candidate code runs with the absolute minimum necessary permissions.
- Static Analysis: Use static analysis tools to automatically detect potential vulnerabilities.
Attack Surface: 2. Denial of Service (DoS) via Candidate Code
- Description: The candidate code path is significantly slower or more resource-intensive than the control path, leading to performance degradation or resource exhaustion.
- Scientist Contribution: Scientist's parallel execution of both code paths means that a slow or resource-hungry candidate code path directly impacts the overall application performance. An attacker could intentionally trigger this.
- Example: An attacker crafts input that triggers a computationally expensive operation (e.g., a complex regular expression or a large database query) in the candidate code, while the control code handles it efficiently.
- Impact: Application slowdown, unavailability, denial of service.
- Risk Severity: High
- Mitigation Strategies:
- Resource Limits & Timeouts: Implement strict resource limits (CPU, memory) and timeouts specifically for the candidate code execution within the Scientist experiment.
- Performance Monitoring: Closely monitor the performance of both paths. Set up alerts for significant discrepancies.
- Circuit Breakers: Implement circuit breakers to automatically disable experiments that consistently exceed resource thresholds.
- Load Testing: Perform load testing that specifically targets the Scientist experiment.
- Rate Limiting: Apply rate limiting to prevent attackers from overwhelming the system.
Attack Surface: 3. Sensitive Data Leakage in Mismatches
- Description: Differences between the control and candidate code results, which are logged or published by Scientist, contain sensitive information.
- Scientist Contribution: Scientist's core function is to compare results and report mismatches. This reporting is the potential leak.
- Example: A mismatch log contains the full, unredacted results from both code paths, including PII or partially hashed passwords.
- Impact: Exposure of personally identifiable information (PII), credentials, or other sensitive data.
- Risk Severity: High
- Mitigation Strategies:
- Custom Comparison Function: Implement a custom comparison function that sanitizes or redacts sensitive information before logging/publishing. Never log raw results.
- Data Minimization: Compare only the essential parts of the results.
- Review Publisher Configuration: Ensure the publisher handles sensitive data appropriately (encryption, access controls).
- Data Loss Prevention (DLP): Consider DLP tools to monitor and prevent leakage.
Attack Surface: 4. Data Exfiltration via Publisher
- Description: The configured publisher for Scientist results is compromised or misconfigured, allowing an attacker to access the comparison data.
- Scientist Contribution: Scientist relies on the publisher to report results. The publisher's security is paramount.
- Example: Scientist publishes to an unauthenticated, publicly accessible endpoint, or a logging service with weak access controls.
- Impact: Exposure of comparison data (potentially including sensitive information) to unauthorized parties.
- Risk Severity: High
- Mitigation Strategies:
- Secure Communication: Use HTTPS for publishing.
- Authentication & Authorization: Implement strong authentication and authorization for the publisher.
- Regular Security Audits: Audit the publisher's security regularly.
- Encryption: Consider encrypting the published data.
- Principle of Least Privilege: Grant the publisher only minimum necessary permissions.
Attack Surface: 5. Injection Attacks in Custom Comparators/Publishers
- Description: Vulnerabilities in custom comparators or publishers allow for injection attacks.
- Scientist Contribution: Scientist allows for custom comparators and publishers, which become part of the attack surface.
- Example: A custom comparator concatenates strings from results without sanitization, leading to string injection.
- Impact: Code execution, data corruption, denial of service (depending on the vulnerability).
- Risk Severity: High
- Mitigation Strategies:
- Code Review: Thoroughly review and test custom comparators/publishers for vulnerabilities.
- Input Validation/Sanitization: Implement robust input validation/sanitization.
- Secure Coding Practices: Follow secure coding practices.