shut down gradio's "everything allowed" CORS policy; I checked the main...

shut down gradio's "everything allowed" CORS policy; I checked the main functionality to work with this, but if this breaks some exotic workflow, I'm sorry.

README.md

@@ -155,14 +155,15 @@ The documentation was moved from this README over to the project's [wiki](https:
 - Swin2SR - https://github.com/mv-lab/swin2sr
 - LDSR - https://github.com/Hafiidz/latent-diffusion
 - Ideas for optimizations - https://github.com/basujindal/stable-diffusion
-- Doggettx - Cross Attention layer optimization - https://github.com/Doggettx/stable-diffusion, original idea for prompt editing.
-- InvokeAI, lstein - Cross Attention layer optimization - https://github.com/invoke-ai/InvokeAI (originally http://github.com/lstein/stable-diffusion)
-- Rinon Gal - Textual Inversion - https://github.com/rinongal/textual_inversion (we're not using his code, but we are using his ideas).
+- Cross Attention layer optimization - Doggettx - https://github.com/Doggettx/stable-diffusion, original idea for prompt editing.
+- Cross Attention layer optimization - InvokeAI, lstein - https://github.com/invoke-ai/InvokeAI (originally http://github.com/lstein/stable-diffusion)
+- Textual Inversion - Rinon Gal - https://github.com/rinongal/textual_inversion (we're not using his code, but we are using his ideas).
 - Idea for SD upscale - https://github.com/jquesnelle/txt2imghd
 - Noise generation for outpainting mk2 - https://github.com/parlance-zz/g-diffuser-bot
 - CLIP interrogator idea and borrowing some code - https://github.com/pharmapsychotic/clip-interrogator
 - Idea for Composable Diffusion - https://github.com/energy-based-model/Compositional-Visual-Generation-with-Composable-Diffusion-Models-PyTorch
 - xformers - https://github.com/facebookresearch/xformers
 - DeepDanbooru - interrogator for anime diffusers https://github.com/KichangKim/DeepDanbooru
+- Security advice - RyotaK
 - Initial Gradio script - posted on 4chan by an Anonymous user. Thank you Anonymous user.
 - (You)

webui.py

@@ -141,6 +141,12 @@ def webui():
         # after initial launch, disable --autolaunch for subsequent restarts
         cmd_opts.autolaunch = False
 
+        # gradio uses a very open CORS policy via app.user_middleware, which makes it possible for
+        # an attacker to trick the user into opening a malicious HTML page, which makes a request to the
+        # running web ui and do whatever the attcker wants, including installing an extension and
+        # runnnig its code. We disable this here. Suggested by RyotaK.
+        app.user_middleware = [x for x in app.user_middleware if x.cls.__name__ != 'CORSMiddleware']
+
         app.add_middleware(GZipMiddleware, minimum_size=1000)
 
         if launch_api: