attack-surface.md

Attack Surface Analysis for sirupsen/logrus

Attack Surface: Log Injection Vulnerabilities

• Description: Attackers inject malicious data into log entries by exploiting the application's use of logrus to log unsanitized user input. This leverages logrus as the mechanism to introduce malicious content into logs.
• Logrus Contribution: logrus directly facilitates the writing of log messages. If developers use logrus to log user-controlled data without proper sanitization, logrus becomes the conduit for log injection attacks.
• Example: An application uses logrus.Infof to log usernames during login attempts, directly embedding the username string. If an attacker provides a username like "admin\n[MALICIOUS_COMMAND]" and this is logged verbatim by logrus, the log file will contain the injected command. If a downstream log processing system parses these logs and is vulnerable to command injection, this malicious command could be executed.
• Impact: Log forgery, log tampering, exploitation of log processing systems (e.g., command injection, SQL injection), complete compromise of systems processing logs, severe damage to log data integrity and trustworthiness.
• Risk Severity: Critical
• Mitigation Strategies:
  • Mandatory Input Sanitization: Enforce strict sanitization or encoding of all user-provided data before it is passed to logrus for logging. Use context-aware escaping based on the log format and downstream consumers.
  • Structured Logging with Fields: Utilize logrus's structured logging features (using logrus.WithFields) to log user data as separate fields, rather than embedding it directly into the log message string. This significantly reduces the risk of injection vulnerabilities by separating data from control characters.
  • Secure Log Consumption: Ensure all systems that process logs generated by logrus are hardened against injection vulnerabilities. Treat log data as potentially untrusted input.

Attack Surface: Information Disclosure of Highly Sensitive Data via Excessive Logging

• Description: logrus is used to log information, and if configured to log at overly verbose levels or if developers mistakenly use logrus to log highly sensitive data (like credentials or cryptographic keys), this information can be exposed in logs.
• Logrus Contribution: logrus's configurable logging levels (Debug, Info, Warn, Error, Fatal, Panic) and ease of use can lead to developers inadvertently logging sensitive information, especially when debug or trace level logging is enabled or when sensitive variables are directly passed to logrus logging functions.
• Example: Developers might use logrus.Debugf to log the entire request body in development, which includes user passwords or API keys. If this debug logging configuration is mistakenly deployed to production, logrus will write these sensitive credentials to production logs, making them accessible to anyone who can access those logs.
• Impact: Exposure of highly sensitive credentials (passwords, API keys, cryptographic keys), full compromise of user accounts or systems, severe data breaches, violation of compliance regulations (e.g., GDPR, PCI DSS).
• Risk Severity: Critical
• Mitigation Strategies:
  • Strictly Minimize Sensitive Data Logging: Absolutely avoid logging highly sensitive data like passwords, API keys, cryptographic keys, and secrets. If logging such data is unavoidable for debugging in development, ensure it is completely disabled and removed for production deployments.
  • Production Logging Level Control: Enforce production logging levels to be at Info, Warn, or Error at most. Disable Debug and Trace logging in production environments. Use configuration management to ensure logging levels are correctly set for each environment.
  • Log Data Auditing and Review: Regularly audit and review log outputs generated by logrus in all environments (especially production) to identify and eliminate any unintentional logging of sensitive information. Implement automated tools to detect patterns of sensitive data in logs.
  • Secure Log Storage and Access Control: Implement the strongest possible access controls for log files and log management systems. Restrict access to logs to only absolutely necessary personnel and use robust authentication and authorization mechanisms.

Attack Surface: Denial of Service (DoS) through Log Flooding via Logrus

• Description: Attackers exploit application logic that, when triggered, causes logrus to generate an excessive volume of log entries, leading to resource exhaustion and service disruption. logrus becomes the tool used to amplify the DoS attack through uncontrolled log generation.
• Logrus Contribution: logrus is the logging mechanism. If application code, when triggered by malicious input or actions, results in a rapid and uncontrolled series of logrus logging calls (e.g., logging every failed authentication attempt without rate limiting), logrus becomes the engine for the log flood.
• Example: An attacker repeatedly sends invalid login requests to an application. If the application uses logrus.Errorf to log every failed login attempt without any rate limiting, a large number of invalid requests will cause logrus to rapidly generate a massive volume of error logs, quickly filling up disk space, consuming I/O bandwidth, and potentially crashing the logging system or the application itself due to resource starvation.
• Impact: Rapid disk space exhaustion, severe performance degradation, application unresponsiveness, log processing system overload or failure, complete service disruption, potential system crashes due to resource starvation.
• Risk Severity: High
• Mitigation Strategies:
  • Implement Rate Limiting for Log Generation: Introduce rate limiting or throttling mechanisms in the application logic to control the frequency of log generation, especially for events triggered by user input or external requests. Prevent logging excessive events in rapid succession.
  • Log Aggregation and Rotation with Resource Limits: Use robust log aggregation and rotation systems with configured resource limits (disk space quotas, buffer sizes) to prevent log flooding from completely exhausting system resources. Configure alerts for high log volume.
  • Review Logging Logic for DoS Vulnerabilities: Proactively review application code and logging logic to identify areas where malicious actors could trigger excessive log generation. Refactor code to prevent or mitigate these scenarios.
  • Resource Monitoring and Alerting: Implement comprehensive monitoring of system resources related to logging (disk space, I/O, CPU usage by logging processes). Set up alerts to detect and respond to sudden spikes in log volume or resource consumption.

Attack Surface: Insecure Configuration of Log Destinations leading to Log Exposure

• Description: logrus allows configuration of various log destinations. If these destinations are misconfigured to be insecure (e.g., publicly accessible network shares, unprotected cloud storage), logs generated by logrus, potentially containing sensitive information, can be exposed to unauthorized access. The misconfiguration of logrus's output is the direct vulnerability.
• Logrus Contribution: logrus's flexibility in configuring log outputs (files, network, cloud services, etc.) means misconfiguration within logrus's settings directly leads to insecure log destinations. Developers using logrus are responsible for securely configuring these outputs.
• Example: A developer configures logrus to send logs to an AWS S3 bucket but fails to properly configure bucket access policies, leaving the bucket publicly readable. Any logs written by logrus to this bucket, potentially including sensitive application data, become accessible to anyone on the internet.
• Impact: Exposure of potentially sensitive log data to unauthorized parties, data breaches, privacy violations, potential compliance violations, reputational damage, enabling further attacks based on exposed information.
• Risk Severity: High
• Mitigation Strategies:
  • Secure Log Destination Configuration: Thoroughly review and securely configure all logrus log destinations. Use secure protocols (HTTPS, SSH, TLS) for network destinations. Implement strong authentication and authorization for cloud storage or log management systems.
  • Principle of Least Privilege for Log Access: Grant access to log destinations (files, storage, systems) only to users and processes that absolutely require it. Use role-based access control and enforce the principle of least privilege.
  • Regular Security Audits of Log Configuration: Conduct regular security audits of logrus logging configurations and destination settings to identify and remediate any misconfigurations or insecure settings. Use automated configuration scanning tools.
  • Log Destination Security Hardening: Harden the security of the chosen log destinations themselves. For example, for file-based logging, ensure appropriate file permissions are set. For cloud storage, enforce strict access policies and encryption.