Affected: gradio-app gradio

Gradio is an open-source Python package that allows quick building of demos and web application for machine learning models, API, or any arbitrary Python function. Prior to version 5.31.0, an arbitrary file copy vulnerability in Gradio's flagging feature allows unauthenticated attackers to copy any readable file from the server's filesystem. While attackers can't read these copied files, they can cause DoS by copying large files (like /dev/urandom) to fill disk space. This issue has been patched in version 5.31.0.

Affected: PyPI: gradio

An arbitrary file copy vulnerability in Gradio's flagging feature allows unauthenticated attackers to copy any readable file from the server's filesystem. While attackers can't read these copied files, they can cause DoS by copying large files (like /dev/urandom) to fill disk space.

### Description The flagging component doesn't properly validate file paths before copying files. Attackers can send specially crafted requests to the `/gradio_api/run/predict` endpoint to trigger these file copies.

**Source**: User-controlled `path` parameter in the flagging functionality JSON payload **Sink**: `shutil.copy` operation in `FileData._copy_to_dir()` method

The vulnerable code flow: 1. A JSON payload is sent to the `/gradio_api/run/predict` endpoint 2. The `path` field within `FileData` object can reference any file on the system 3. When processing this request, the `Component.flag()` method creates a `GradioDataModel` object 4. The `FileData._copy_to_dir()` method uses this path without proper validation:

```python def _copy_to_dir(self, dir: str) -> FileData: pathlib.Path(dir).mkdir(exist_ok=True) new_obj = dict(self)

if not self.path: raise ValueError("Source file path is not set") new_name = shutil.copy(self.path, dir) # vulnerable sink new_obj["path"] = new_name return self.__class__(**new_obj) ``` 5. The lack of validation allows copying any file the Gradio process can read

### PoC The following script demonstrates the vulnerability by…