GitHub Security Advisory: GHSA-q279-jhrf-cc6v
Package: ray (PIP)
Severity: CRITICAL (CVSS 0.0)
CWE: CWE-94: Improper Control of Generation of Code ('Code Injection'), CWE-352: Cross-Site Request Forgery (CSRF)
Vulnerable versions: < 2.52.0
Patched in: 2.52.0

Summary: Ray is vulnerable to Critical RCE via Safari & Firefox Browsers through DNS Rebinding Attack

Details:
# Summary

Developers working with Ray as a development tool can be exploited via a critical RCE vulnerability exploitable via Firefox and Safari. 

Due to the longstanding [decision](https://docs.ray.io/en/releases-2.51.1/ray-security/index.html) by the Ray Development team to not implement any sort of authentication on critical endpoints, like the `/api/jobs` & `/api/job_agent/jobs/` has once again led to a severe vulnerability that allows attackers to execute arbitrary code against Ray. This time in a development context via the browsers Firefox and Safari.

This vulnerability is due to an insufficient guard against browser-based attacks, as the current defense uses the `User-Agent` header starting with the string "Mozilla" as a defense mechanism. This defense is insufficient as the fetch specification allows the `User-Agent` header to be modified.

Combined with a DNS rebinding attack against the browser, and this vulnerability is exploitable against a developer running Ray who inadvertently visits a malicious website, or is served a malicious advertisement ([malvertising](https://en.wikipedia.org/wiki/Malvertising)).

# Details

The mitigations implemented to protect against browser based attacks against local Ray nodes are insufficient.

## Current Mitigation Strategies

```python
def is_browser_request(req: Request) -> bool:
    """Checks if a request is made by a browser like user agent.

    This heuristic is very weak, but hard for a browser to bypass- eg,
    fetch/xhr and friends cannot alter the user-agent, but requests made with
    an http library can stumble into this if they choose to user a browser like
    user agent.
    """
    return req.headers["User-Agent"].startswith("Mozilla")


def deny_browser_requests() -> Callable:
    """Reject any requests that appear to be made by a browser"""

    def decorator_factory(f: Callable) -> Callable:
        @functools.wraps(f)
        async def decorator(self, req: Request):
            if is_browser_request(req):
                return Response(
                    text="Browser requests not allowed",
                    status=aiohttp.web.HTTPMethodNotAllowed.status_code,
                )
            return await f(self, req)

        return decorator

    return decorator_factory
```

https://github.com/ray-project/ray/blob/f39a860436dca3ed5b9dfae84bd867ac10c84dc6/python/ray/dashboard/optional_utils.py#L129-L155

```python
    @aiohttp.web.middleware
    async def browsers_no_post_put_middleware(self, request, handler):
        if (
            # A best effort test for browser traffic. All common browsers
            # start with Mozilla at the time of writing.
            dashboard_optional_utils.is_browser_request(request)
            and request.method in [hdrs.METH_POST, hdrs.METH_PUT]
        ):
            return aiohttp.web.Response(
                status=405, text="Method Not Allowed for browser traffic."
            )

        return await handler(request)
```
https://gi