Multi Step Form WordPress Plugin Arbitrary File Upload Vulnerability

A vulnerability allowing arbitrary file uploads has been identified in the Multi Step Form plugin for WordPress, affecting all versions through 1.7.25. The issue arises from inadequate file type validation in the import feature, which enables authenticated attackers with Administrator-level access to upload potentially malicious files to the server. This vulnerability could be exploited to execute remote code.

Impact

The vulnerability could be exploited to upload files containing PHP code, which could then be executed on the server, leading to remote code execution.

Reproduction

To reproduce this vulnerability, an authenticated user with Administrator privileges can upload a file through the JSON import feature of the Multi Step Form plugin. The uploaded file can be a JSON file that includes PHP code, which the plugin's previous version would not have properly validated or sanitized.

Remediation

Users are advised to update the Multi Step Form plugin to version 1.7.26 or later.