AWS CodeBuild Exposure Scanner

AWS CodeBuild is a fully managed build service that compiles source code, runs tests, and produces software packages ready to deploy. It is widely used by developers and IT operations teams to automate the build and release process of applications. The service is known for its scalability and ability to handle concurrent builds. Developers use AWS CodeBuild to integrate with other AWS services and tools, streamlining the continuous integration and continuous delivery (CI/CD) process. The buildspec.yml file is integral to defining the build process and configurations within AWS CodeBuild. Organizations rely on AWS CodeBuild to bolster their DevOps practices, ensuring efficient software delivery.

This scanner detects the exposure of AWS CodeBuild's buildspec.yml file within a digital asset. The buildspec.yml file contains essential commands and settings for the build process, which, if exposed, can lead to security risks. Exposure of such files can occur due to misconfigurations or lack of secure access control, revealing sensitive data or system information. The vulnerability arises because the file might disclose details of the build process and underlying infrastructure, making it crucial to detect and secure such exposures. Being a detection template, it does not exploit the vulnerability but flags its presence for further security review.

The technical details of the vulnerability involve locating accessible endpoints hosting AWS CodeBuild's buildspec.yml file. The scanner checks for specific file paths like '/buildspec.yml' and '/buildspec.yaml' and looks for key contents like 'version:', 'phases:', 'build:', and 'commands:' within the file. It inspects the HTTP response headers to verify MIME types such as 'text/yaml' or 'application/x-yaml'. Upon matching these parameters, the presence of the file is confirmed, indicating potential exposure. The detection is critical as it provides an early warning to rectify any exposure issues.

When exploited, the exposure of the buildspec.yml file could result in unauthorized access to detailed information about the application's build process and infrastructure. This could potentially allow attackers to understand the build commands and potentially craft malicious commands. Moreover, sensitive configurations or secrets contained within the file could be leaked, leading to further exploitation. Ultimately, it can weaken the security posture of the entire application lifecycle, making timely detection and remediation imperative.

REFERENCES

• https://docs.aws.amazon.com/codebuild/latest/userguide/build-spec-ref.html