CVE-2026-55419

## Summary The Reachy Mini daemon exposes the “/api/media/sounds/upload” endpoint without authentication and file validation mechanisms. An attacker can use this endpoint to upload malicious files into the file system that will propagate in future attacks. ## Compromise Chain: Unauthenticated to Full Root Access This issue is part of a full compromise chain allowing an unauthenticated user to gain root access on the Reachy’s operating system: 1. Unrestricted File Upload in Media Sounds Upload API \<= current finding 2. Bluetooth Authentication Bypass 3. Bluetooth Directory Traversal ## Description The root cause of the issue is at the handler located in “***src/daemon/app/routers/media.py***” file at the “upload\_sound” method: ```py @router.post("/sounds/upload") async def upload_sound( file: UploadFile = File(...), ) -> dict[str, str]: """Upload a sound file to the daemon's temporary sound directory. The file is saved to ``/tmp/reachy_mini_sounds/<original_filename>``. If a file with the same name already exists it is overwritten. Returns: JSON with the absolute *path* of the saved file on the daemon. """ if not file.filename: raise HTTPException(status_code=400, detail="Filename is required") # Reject path traversal filename = Path(file.filename).name if not filename or filename in (".", ".."): raise HTTPException(status_code=400, detail="Invalid filename") os.makedirs(SOUNDS_TMP_DIR, exist_ok=True) dest = os.path.join(SOUNDS_TMP_DIR, filename) content = await file.read() with open(dest, "wb") as f: f.write(content) return {"status": "ok", "path": dest} ``` This endpoint lacks multiple defence mechanisms: 1. No authentication mechanism. 2. No file extension validation. 3. No file content/size validation. Additionally, the daemon is bound to the 0.0.0.0 network interfaces (a.k.a. all network interfaces) by default along with permissive CORS ( allow\_ori