Horizon Alert
Summary of the vulnerability and why it matters
This advisory concerns a vulnerability in a code generation tool for FastAPI applications. The tool incorrectly handles certain input, potentially allowing malicious code to be embedded and executed when the generated code is used. While the tool itself is not directly part of a deployed application, its output could be affected if not properly managed during the development or build process.
- Code generation flaw allows embedded malicious code.
- Affects tools generating code from OpenAPI.
- Confirm relevance and exposure in development pipelines.
Attack Path
How an attacker could exploit the issue
An attacker could influence the OpenAPI specification used to generate FastAPI code. If this specification contains crafted input, the generated code might include executable Python code. This code would run with the privileges of the application or the CI process when the generated code is imported.
- Attacker influences OpenAPI specification.
- Generated code executes arbitrary Python.
- Risk of code execution with application privileges.
Live Threat
Current exploitation, exposure, and threat context
When an attacker influences an OpenAPI path, it could be injected as executable Python code into a route decorator during application generation. This occurs when the generated module is imported and the decorator is evaluated, potentially allowing the code to run with the privileges of the application or CI process.
- Application generation code could be affected.
- Malicious input in OpenAPI paths.
- Arbitrary code execution within the generation environment.
Operational Fix
Recommended remediation, mitigation, and detection steps
Teams responsible for application development pipelines or code generation processes should prioritize addressing this vulnerability. The first practical step involves identifying all instances where `fastapi-code-generator` is used in the development or CI/CD workflow, confirming if the generated code is imported and executed, and locating the development or platform team accountable for its integration. Remediation planning should then be based on the risk of code injection during the generation phase.
- Application development and CI/CD teams own this.
- Verify if generated code is imported and executed.
- Plan remediation based on identified risks.
