Arbitrary Local File Read via Component Method Invocation in gradio-app/gradio

An issue was discovered in gradio-app/gradio, where the /component_server endpoint improperly allows the invocation of any method on a Component class with attacker-controlled arguments. Specifically, by exploiting the move_resource_to_block_cache() method of the Block class, an attacker can copy any file on the filesystem to a temporary directory and subsequently retrieve it. This vulnerability enables unauthorized local file read access, posing a significant risk especially when the application is exposed to the internet via launch(share=True), thereby allowing remote attackers to read files on the host machine. Furthermore, gradio apps hosted on huggingface.co are also affected, potentially leading to the exposure of sensitive information such as API keys and credentials stored in environment variables.