CONFIDENTIAL

KL-CAN-2024-002

Vulnerability Details

#	Field	Value
1	Discoverer	Jaggar Henry & Sean Segreti of KoreLogic, Inc.
2	Date Submitted	2024.03.12
3	Title	Open WebUI Arbitrary File Upload + Path Traversal
5	Affected Vendor	Open WebUI
6	Affected Product(s)	Open WebUI (Formerly Ollama WebUI)
7	Affected Version(s)	0.1.105
8	Platform/OS	Debian GNU/Linux 12 (bookworm)
9	Vector	HTTP web interface
10	CWE	CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), CWE-434: Unrestricted Upload of File with Dangerous Type

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4. High-level Summary

Attacker controlled files can be uploaded to arbitrary locations on the web server's filesystem by abusing a path traversal vulnerability.

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11. Technical Analysis

When attaching files to a prompt by clicking the plus sign (+) on the left of the message input box when using the Open WebUI HTTP interface, the file is uploaded to a static upload directory.

The name of the file is derived from the original HTTP upload request and is not validated or sanitized. This allows for users to upload files with names containing dot-segments in the file path and traverse out of the intended uploads directory. Effectively, users can upload files anywhere on the filesystem the user running the web server has permission.

This can be visualized by examining the python code for the /rag/api/v1/doc API route:

@app.post("/doc")
def store_doc(
    collection_name: Optional[str] = Form(None),
    file: UploadFile = File(...),
    user=Depends(get_current_user),
):
    # "https://www.gutenberg.org/files/1727/1727-h/1727-h.htm"

    print(file.content_type)
    try:
        filename = file.filename
        file_path = f"{UPLOAD_DIR}/{filename}"
        contents = file.file.read()
        with open(file_path, "wb") as f:
            f.write(contents)
            f.close()