Executive brief
A vulnerability exists in the LocalStack plugin for the Serverless Framework, which is used by developers to simulate AWS cloud environments locally. An attacker who can modify the project's configuration file can execute arbitrary commands on the developer's machine or within a CI/CD build environment. This could lead to the theft of sensitive credentials, source code, or full system compromise during the deployment process.
Technical details
An OS command injection vulnerability exists in serverless-localstack versions up to 1.4.0 within the Configuration Handler component (src/index.js). The issue stems from the improper neutralization of the 'custom.localstack.docker.compose_file' configuration value, which is directly interpolated into a shell command string using 'exec()' when the 'autostart' feature is enabled. Because the plugin does not escape shell metacharacters or use an argument array for the 'docker-compose' command, a local attacker or a malicious actor capable of influencing the Serverless configuration can achieve arbitrary code execution. This typically occurs when a developer or CI/CD runner executes a Serverless command in a project with a compromised configuration. As of the advisory date, the project has been notified but a formal patch has not been confirmed.
Affected products
- LocalStack serverless-localstack up to 1.4.0
Timeline
- 2026-06-17: disclosed: Issue reported to the project maintainers via GitHub issue #303
- 2026-07-23: advisory: Vulnerability published in NVD/VulDB