The Geo Mashup plugin for WordPress is vulnerable to Time-Based SQL Injection via the 'sort' parameter in all versions up to, and including, 1.13.18. This is due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. The `esc_sql()` function is applied but is ineffective in the `ORDER BY` context because the value is not enclosed in quotes. Additionally, while a `sanitize_sort_arg()` allowlist-based sanitizer was added in version 1.13.18, it is only applied in the AJAX code path (`sanitize_query_args()`) and not in the `render-map.php` or template tag code paths. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database via a time-based blind approach.