Language: PHP
Label: vulnerable
CWE: CWE-79 \u2014 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Code:
function save_query($query) {
    global $table_prefeix;	// table prefix;
    global $conn;			// MySQL connection variable.
    $query = json_encode($query);
    $conn->query("INSERT INTO {$table_prefeix}latest_queries (query_value) VALUES ($query)");

}