Vvveb before 1.0.8.3 contains an unrestricted file upload vulnerability in the plugin upload endpoint that allows super_admin users to execute arbitrary PHP code by uploading a malicious plugin ZIP file. Attackers can craft a ZIP containing a plugin.php with a valid Slug header and a public/index.php file with arbitrary PHP code, which executes as the web server user once accessed via subsequent unauthenticated HTTP requests to the plugin's public path.