Cross-site Scripting on Gradio server via upload of HTML files, JS files, or SVG files

Summary

Gradio is an open-source Python package designed for quick prototyping. This vulnerability involves **Cross-Site Scripting (XSS)** on any Gradio server that allows file uploads. Authenticated users can upload files such as HTML, JavaScript, or SVG files containing malicious scripts. When other users download or view these files, the scripts will execute in their browser, allowing attackers to perform unauthorized actions or steal sensitive information from their sessions. This impacts any Gradio server that allows file uploads, particularly those using components that process or display user-uploaded files. Users are advised to upgrade to `gradio>=5` to address this issue. As a workaround, users can restrict the types of files that can be uploaded to the Gradio server by limiting uploads to non-executable file types such as images or text. Additionally, developers can implement server-side validation to sanitize uploaded files, ensuring that HTML, JavaScript, and SVG files are properly handled or rejected before being stored or displayed to users.