Log2Space Subscriber Management Software 1.1 is vulnerable to unauthenticated SQL injection via the `lead_id` parameter in the `/l2s/api/selfcareLeadHistory` endpoint. A remote attacker can exploit this by sending a specially crafted POST request, resulting in the execution of arbitrary SQL queries. The backend fails to sanitize the user input, allowing enumeration of database schemas, table names, and potentially leading to full database compromise.