* fix(security): close DNS-rebinding hole on diffusion_server
scripts/diffusion_server.py used to ship `allow_origins=["*"]` with the
default `--host=127.0.0.1` bind. Combined, that left the OpenAI-compatible
image API reachable from any browser tab via DNS-rebinding: an attacker page
resolves its own domain to 127.0.0.1 mid-fetch, the browser forwards the
request to the loopback server, the server processes it (no Host check), and
the wildcard CORS reply lets the attacker page read the result + drive the
GPU. CWE-346 + CWE-942 + CWE-352 (DNS-rebinding bridge).
Fix:
- Drop the wildcard CORS at module load (default-deny).
- Install `TrustedHostMiddleware` with a loopback allowlist so DNS-rebound
requests are rejected by the middleware before any route runs.
- Add additive `--allowed-host` / `--allowed-origin` CLI flags so operators
who need browser access on a specific origin can opt in explicitly without
re-introducing the wildcard.
Tests: tests/test_diffusion_server_security.py (9 cases) pin the allowlist
helpers, the default-deny CORS behavior, and the live middleware paths via
Starlette's TestClient.
Detected by Aeon + semgrep + manual review.
Severity: medium.
CWE-346 / CWE-942 / CWE-352.
* test(diffusion-server): drive ASGI app via httpx, not TestClient portal
The TrustedHost/CORS integration tests used `with TestClient(app) as
client:`, whose context-manager form spins up an anyio blocking portal to
run the app lifespan. Under the repo's pytest setup (anyio plugin active, a
stray asyncio_mode option, no pytest-asyncio) that portal deadlocks —
`test_trusted_host_middleware_rejects_attacker_host` hung indefinitely in
review before emitting any assertion output.
Replace the TestClient usage with a tiny _asgi_get() helper that drives the
ASGI app over httpx.ASGITransport on a fresh event loop (asyncio.run). No
portal, no lifespan, no dependency on the host project's async test plugins.
Host is taken from the request URL so TrustedHostMiddleware sees the exact
hostname under test; Origin goes through headers. Assertions are unchanged.
Focused test now passes in 0.12s; full file 9 passed.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---------
Co-authored-by: aeonframework <aeonframework@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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