Arbitrary File Write by Prompt Injection via DuckDB SQL in vanna-ai/vanna

Vanna v0.3.4 is vulnerable to SQL injection in its DuckDB integration exposed to its Flask Web APIs. Attackers can inject malicious SQL training data and generate corresponding queries to write arbitrary files on the victim's file system, such as backdoor.php with contents `<?php system($_GET[0]); ?>`. This can lead to command execution or the creation of backdoors.