Gradio's `is_in_or_equal` function may be bypassed

Impact

What kind of vulnerability is it? Who is impacted?

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.

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 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.