Gradio's CORS origin validation accepts the null origin

Impact

What kind of vulnerability is it? Who is impacted?

This vulnerability relates to CORS origin validation accepting a null origin. When a Gradio server is deployed locally, the localhost_aliases variable includes "null" as a valid origin. This allows attackers to make unauthorized requests from sandboxed iframes or other sources with a null origin, potentially leading to data theft, such as user authentication tokens or uploaded files. This impacts users running Gradio locally, especially those using basic authentication.

Patches

Yes, please upgrade to gradio>=5.0 to address this issue.

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

As a workaround, users can manually modify the localhost_aliases list in their local Gradio deployment to exclude "null" as a valid origin. By removing this value, the Gradio server will no longer accept requests from sandboxed iframes or sources with a null origin, mitigating the potential for exploitation.