Flowise File Upload Vulnerability Allowing Remote Code Execution

A vulnerability in Flowise prior to version 3.1.0 allows for unauthorized file uploads by bypassing MIME type validation. The Chatflow configuration can be manipulated to accept JavaScript files, which are normally restricted. This flaw enables attackers to upload malicious Node.js web shells that could be executed on the server, potentially leading to remote code execution.

Impact

Exploitation of this vulnerability allows for the persistent upload of malicious web shells that can be executed on the server, resulting in remote code execution. This poses a significant threat to the integrity and confidentiality of the system.

Reproduction

To reproduce this vulnerability, first, modify the Chatflow configuration to accept 'application/javascript' as a valid upload MIME type. This can be done by sending a PUT request to the Chatflow API with the appropriate configuration data. Once JavaScript file uploads are enabled, upload a .js file containing a web shell payload as an attachment to the Chatflow. The uploaded web shell can then be accessed and executed via a crafted HTTP request.

Remediation

Users are advised to update Flowise to version 3.1.0 or later, where this vulnerability has been fixed.