Securing CI/CD Environments: Insights from CISA and NSA Guidance

Guidance on Securing CI/CD Environments

Introduction

The Cybersecurity and Infrastructure Security Agency (CISA) and the National Security Agency (NSA) have joined forces to provide guidance for organizations on how to secure continuous integration and continuous delivery (CI/CD) pipelines against malicious attacks. CI/CD is a crucial component of the DevSecOps approach, which aims to integrate automation and security throughout the development lifecycle. The increasing adoption of cloud technologies has led to the implementation of CI/CD pipelines in commercial cloud environments, making them attractive targets for threat actors seeking to inject malicious code, steal sensitive information, or cause denial-of-service attacks.

Threats to CI/CD Environments

According to CISA and the NSA, some of the security threats to CI/CD environments include insecure first-party and third-party code, poisoned pipeline execution, insufficient pipeline access controls, insecure system configurations, the use of insecure third-party services, and exposure of secrets. Threat actors can exploit vulnerabilities in CI/CD pipelines by introducing insecure code, compromising source code repositories, exploiting weak access controls or misconfigurations, and abusing third-party services. These threats pose significant risks to the integrity and security of organizations’ software development processes.

Recommendations for Hardenign CI/CD Environments

CISA and the NSA have provided several recommendations and best practices to help organizations strengthen their CI/CD environments and enhance their DevSecOps practices. These recommendations include:

1. Use strong cryptographic algorithms: Organizations should employ robust cryptographic algorithms to secure their cloud applications and services, thereby protecting sensitive data from unauthorized access or tampering.

2. Use strong credentials: It is essential to use strong and unique credentials, such as passwords and authentication tokens, to prevent unauthorized access to CI/CD pipelines.

3. Add signatures to CI/CD configurations: Implementing digital signatures for CI/CD configurations adds an extra layer of security and ensures the integrity and authenticity of the pipeline.

4. Implement two-person rules (2PR) for code updates: Requiring the involvement of two authorized individuals for approving and deploying code changes helps mitigate the risk of insider threats and unauthorized modifications.

5. Implement least-privilege policies: Organizations should adopt the principle of least privilege, granting users only the necessary permissions to perform their tasks within the CI/CD environment. This minimizes the attack surface and reduces the potential impact of a compromised account.

6. Implement network segmentation: By dividing the CI/CD infrastructure into separate network segments, organizations can limit the lateral movement of threat actors within the environment, preventing them from accessing critical resources.

7. Audit and secure secrets and user credentials: Organizations should regularly audit and secure secrets, such as API keys, passwords, and encryption keys, used in their CI/CD pipelines. Encryption and secure storage must be utilized to prevent unauthorized access to these sensitive assets.

Further Recommendations and Best Practices

In addition to the above recommendations, CISA and the NSA suggest the following measures to enhance the security of CI/CD environments:

1. Keep operating systems, software, and CI/CD tools up to date: Regularly applying patches and updates to infrastructure components minimizes the risk of known vulnerabilities being exploited.

2. Remove unnecessary applications: Eliminating unused or unnecessary applications and services reduces the potential attack surface and minimizes the exposure to potential vulnerabilities.

3. Use malware detection tools: Implementing robust malware detection tools helps identify and mitigate any potential threats within the CI/CD environment.

4. Integrate security scanning into the CI/CD pipeline: Conducting security scans and vulnerability assessments as part of the CI/CD pipeline can identify and address vulnerabilities and weaknesses in code before deployment.

5. Restrict the use of untrusted code: Organizations should exercise caution when using third-party code and ensure that it comes from trusted sources.

6. Analyze committed code: Conducting code reviews and analyzing committed code can help identify potential security flaws and vulnerabilities early in the development process.

7. Remove temporary resources: Managing and removing temporary resources, such as test environments and development artifacts, reduces the attack surface and minimizes the potential exposure of sensitive information.

8. Implement software bill of materials (SBOM) and software composition analysis (SCA): These tools can help organizations identify and track the software components used in their CI/CD pipelines, enabling them to monitor and address any known vulnerabilities promptly.

Conclusion

The joint guidance from CISA and the NSA provides valuable recommendations and best practices for securing CI/CD environments against malicious attacks. By implementing these mitigations, organizations can significantly reduce the number of exploitation vectors and create a challenging environment for threat actors to penetrate. However, organizations must understand that security is an ongoing process, and they should continuously evaluate and update their security measures to stay one step ahead of evolving threats.