Enhancing CI/CD Pipeline Security with Hardening, Network Audit and Zero Trust

In modern software development, Continuous Integration and Continuous Deployment (CI/CD) pipelines are the backbone of rapid and reliable software delivery. However, they have also become prime targets for sophisticated cyber threats, including code injection and secrets exfiltration. Understanding these risks and implementing robust hardening strategies is crucial for maintaining the integrity of your software supply chain.

Understanding the Risks in CI/CD Pipelines

Code Injection Attacks

Scenario: Attackers exploit vulnerabilities in your pipeline to inject malicious code. This can occur through compromised dependencies or vulnerable actions.

Impact:

• Deployment of Compromised Applications: Malicious code becomes part of your production software, potentially introducing backdoors or data leaks.

• Reputation Damage: Users lose trust in your software due to security breaches.

Secret Exfiltration

Scenario: CI/CD pipelines often handle sensitive information such as API keys, certificates, and credentials. Attackers may attempt to exfiltrate these secrets by intercepting them during the build process or through malicious scripts.

Impact:

• Unauthorized Access: Compromised secrets can grant attackers access to critical infrastructure.

• Data Breaches: Exposure of confidential user or company data.

Hardening the CI/CD Pipeline

To mitigate these risks, a comprehensive hardening strategy should be employed across all components of the CI/CD environment, particularly the build runners.

The Importance of Operating System Hardening

Operating system (OS) hardening secures systems by reducing vulnerabilities through disabling unnecessary software and services, and configuring security settings. In CI/CD pipelines, runners execute workflows and have access to sensitive assets like source code and credentials, making them critical to secure.

Key OS Hardening Practices:

• Disable Unnecessary Services

• Regularly Update and Patch Systems

• Configure Firewalls and Network Settings

Example: Disabling RDP on Windows Runners

Remote Desktop Protocol (RDP) allows remote connections to computers but poses security risks if enabled on CI/CD runners. It's enabled by default even on standard GitHub runners…

Risks Associated with RDP:

• Unauthorized Access: Attackers exploiting vulnerabilities or using brute-force attacks.

• Lateral Movement: Attackers moving to other systems within the network.

• Data Exfiltration: Access to code and secrets on the runner.

Ensuring Proper Network Segmentation

• Isolate Runners: Place runners in secured network segments with strict access controls.

• Limit Connectivity: Only allow necessary inbound and outbound connections.

Introducing edamame_posture_action

The edamame_posture_action is a GitHub Action designed to enhance the security of your CI/CD pipelines through rigorous hardening and monitoring.

Key Features

• Zero Trust Integration: Aligns with Zero Trust principles, ensuring continuous verification of the security posture.

• Automated Hardening: Enforces security policies by disabling unnecessary services and configuring secure settings.

• Network Segmentation Validation: Verifies that runners are configured with proper network isolation.

• Comprehensive Traffic Capture: Captures all network packets entering and exiting the GitHub runner.

• Detailed Audit Trails: Provides logs in Zeek format for in-depth network analysis

  
  

Real-World Threat Scenarios

Example 1: Malicious Dependency Injection

An open-source library used in your project is compromised. The attacker introduces malicious code that, when built in your CI/CD pipeline, infects your application.

Mitigation with edamame_posture_action:

• Traffic Analysis: Detects unusual outbound connections initiated by the compromised pipeline during the build.

Example 2: Secret Exfiltration via Rogue Scripts

An insider or external attacker injects a script into the pipeline that attempts to send environment variables to an external server.

Mitigation with edamame_posture_action:

• Packet Capture: Logs all outbound requests, including attempts to exfiltrate data.

• Zeek Analysis: Facilitates detection of anomalies including DNS Data based exfiltration

Integrating edamame_posture_action into Your Workflow

To leverage the capabilities of edamame_posture_action, integrate it into your GitHub Actions workflow:

Configuration Options

• network_scan: Enables scanning of the runner's network environment for unauthorized devices or connections.

• auto_remediate: Automatically applies fixes to identified security issues.

• dump_sessions_log: A post processing step that provides comprehensive session logs for audit and compliance purposes.

Aligning with Zero Trust Principles

The action is part of EDAMAME's broader Zero Trust approach to the Software Development Lifecycle (SDLC). It ensures that:

• Every Device is Verified: All devices interacting with code repositories are assessed for compliance with security policies.

• Continuous Monitoring: Security posture is continuously monitored, and any deviations trigger alerts or automatic remediation.

• Developer Productivity is Maintained: Security enhancements are implemented without hindering the development process.

Conclusion

Securing CI/CD pipelines requires a multifaceted approach that addresses both the technological and process-oriented aspects of software development. The edamame_posture_action provides a powerful tool for specialists aiming to enhance their pipeline security through:

• Automated Hardening: Enforces best practices without manual intervention.

• Comprehensive Monitoring: Full visibility into network activities within the runner environment.

• Risk Mitigation: Create an audit trail for code injection and secret exfiltration attempts.

By integrating such tools and adhering to Zero Trust principles, organizations can significantly reduce their exposure to supply chain attacks and safeguard the integrity of their software delivery processes.