The vulnerability description indicates improper path sanitization in upload requests to the Skipper server API. The PackageController.upload endpoint would be the primary entry point for upload operations, while DefaultPackageService.upload would handle the actual file writing logic. The combination of these functions likely constructs file paths using untrusted user input without proper validation against path traversal sequences (CWE-22). The arbitrary file write capability could subsequently enable code injection (CWE-94) if malicious files are written to executable locations. The confidence is high as these components directly align with the described attack vector and typical Spring Cloud Data Flow architecture.