CVE-2024-47164: Gradio: path traversal bypasses directory access controls

Gradio is an open-source Python package designed for quick prototyping. This vulnerability relates to the **bypass of directory traversal checks** within the `is_in_or_equal` function. This function, intended to check if a file resides within a given directory, can be bypassed with certain payloads that manipulate file paths using `..` (parent directory) sequences. Attackers could potentially access restricted files if they are able to exploit this flaw, although the difficulty is high. This primarily impacts users relying on Gradio’s blocklist or directory access validation, particularly when handling file uploads. Users are advised to upgrade to `gradio>=5.0` to address this issue. As a workaround, users can manually sanitize and normalize file paths in their Gradio deployment before passing them to the `is_in_or_equal` function. Ensuring that all file paths are properly resolved and absolute can help mitigate the bypass vulnerabilities caused by the improper handling of `..` sequences or malformed paths.

An adversary scans for public-facing Gradio deployments via Shodan or Censys using Gradio-specific HTTP response fingerprints. They identify a research team's model demo endpoint running gradio 4.x. By crafting a file upload request with a path parameter containing '../../.huggingface/token' or '../../app/.env', they bypass the is_in_or_equal directory check and retrieve the file contents in the HTTP response. The attacker now has the team's Hugging Face API token, enabling them to clone private models, access private datasets, or pivot to other services authenticated with the same token. The full attack chain takes under 5 minutes and requires no specialized ML knowledge.