Attack Surface Analysis for uber-go/zap

Attack Surface: Log Injection/Forging

1. Log Injection/Forging
- Description: Attackers inject malicious content into log entries by manipulating application inputs that are subsequently logged. This can mislead investigations, trigger false alerts, or even exploit vulnerabilities in log analysis tools.
- How zap Contributes: zap provides the mechanism for logging data. If user-supplied data is directly included in log messages without sanitization, zap becomes the conduit for the injected content. This is the primary direct attack surface of zap.
- Example:
  - An application logs user login attempts: logger.Info("Login attempt for user: " + username).
  - An attacker provides a username like: admin\n[ERROR] Database connection failed.
  - The log now contains a misleading error message, potentially masking a real attack.
- Impact:
  - Bypass of security monitoring.
  - Triggering of false positives in security systems.
  - Potential exploitation of vulnerabilities in log analysis tools (though this is indirectly related to zap).
  - Data exfiltration (indirectly, through vulnerable log parsers).
  - Denial of Service on the logging system.
- Risk Severity: Critical (if user input is directly logged) / High (if some sanitization is present but insufficient).
- Mitigation Strategies:
  - Mandatory Structured Logging: Always use zap's structured logging features (e.g., logger.Info("Login attempt", zap.String("username", username))). This treats user input as data, not part of the log message template. This is the single most important mitigation.
  - Input Validation: Implement rigorous input validation before logging. Reject or sanitize any input containing unexpected characters or patterns. This is a general security best practice, but crucial here.
  - Encoding (as a fallback): If absolutely necessary to log potentially problematic characters, encode them (e.g., URL encoding, Base64) before passing them to zap. This is less preferred than strict structured logging.
  - Rate Limiting: Implement rate limiting on logging to prevent attackers from flooding the system with malicious log entries (DoS mitigation).
  - Contextual Logging: Add contextual information (request ID, user ID) to aid in tracing.

Attack Surface: Sensitive Data Exposure in Configuration

2. Sensitive Data Exposure in Configuration
- Description: zap's configuration (e.g., sink settings, encoder options) might inadvertently contain sensitive information like API keys, passwords, or internal network addresses. Exposure of this configuration can lead to compromise.
- How zap Contributes: zap requires configuration to define its behavior (sinks, encoders, etc.). If this configuration includes secrets and is not properly protected, zap's configuration mechanism is directly involved in the exposure.
- Example:
  - A zap configuration file includes a database password for a logging sink:
```
{
  "outputPaths": ["db://user:password@host:port/database"]
}
```
  - This file is accidentally committed to a public source code repository.
- Impact:
  - Compromise of sensitive credentials.
  - Unauthorized access to internal systems.
  - Data breaches.
- Risk Severity: Critical
- Mitigation Strategies:
  - Never Hardcode Secrets: Absolutely avoid hardcoding sensitive information directly in zap configuration files.
  - Environment Variables: Use environment variables to store sensitive configuration values and load them programmatically.
  - Secrets Management: Employ a dedicated secrets management solution (e.g., HashiCorp Vault, AWS Secrets Manager, Azure Key Vault) to securely store and retrieve secrets.
  - Configuration File Permissions: Ensure that configuration files have restrictive file permissions to prevent unauthorized access.
  - Configuration Validation: Implement checks to ensure that the loaded configuration does not contain any obvious secrets or misconfigurations.

Attack Surface: Misconfigured Logging Sinks

3. Misconfigured Logging Sinks
- Description: Incorrectly configured output sinks (e.g., files, network sockets, external services) can lead to logs being sent to unintended or insecure destinations, exposing sensitive information.
- How zap Contributes: zap provides the functionality to send logs to various sinks. Misconfiguration of these sinks, a direct setting within zap, is the root cause of this attack surface.
- Example:
  - A zap sink is configured to send logs to a publicly accessible web server directory.
  - An attacker can access the logs and potentially gain sensitive information.
- Impact:
  - Unintentional data exposure.
  - Potential for network-based attacks if logs are sent to an attacker-controlled server.
  - Denial of Service if the sink is slow or unavailable.
- Risk Severity: High
- Mitigation Strategies:
  - Thorough Sink Review: Carefully review and test all sink configurations to ensure they are sending logs to the correct and secure destinations. This is paramount.
  - Secure Protocols: Use secure protocols (e.g., TLS/SSL) when sending logs over a network.
  - Least Privilege: Configure sinks with the minimum necessary permissions. A file sink should only have write access to the specific log file, for example.
  - Sink Monitoring: Monitor the performance and availability of logging sinks.
  - Network Segmentation: If sending logs over a network, use network segmentation to isolate the logging traffic.