Title: Payment bypass  
Product: WordPress NAB Transact WooCommerce Plugin  
Vendor Homepage:  
Vulnerable Version: 2.1.0  
Fixed Version: 2.1.2  
CVE Number: CVE-2020-11497  
Author: Jack Misiura from The Missing Link   
2020-03-27 Disclosed to Vendor  
2020-03-29 Vendor publishes first fix  
2020-04-04 Vendor publishes second fix  
2020-08-17 Fix confirmed  
2020-08-20 Publication  
1. Vulnerability Description  
The WordPress NAB Transact WooCommerce plugin does not validate the origin of payment processor status requests, allowing orders to be marked as fully paid by issuing a specially crafted GET request during the ordering workflow.  
2. PoC  
When presented with a payment screen, instead of submitting payment information, issue the following GET request to the site:   wc_order_YYYYY&is_crn=0&txnid=ZZZZZ&refid=WooCommerceXXXX&rescode=00&restext=Approved  
Where XXXX is the order number and YYYY is the order code which have been present before during the workflow. If these are not presented, submit invalid payment information and get a declined message. Now brute-force the order number which is sequential. Doing so will mark any existing pending orders as fully paid.  
3. Solution  
The vendor provides an updated version (2.1.2) which should be installed immediately.  
4. Advisory URL    
Jack Misiura​  
Application Security Consultant  
9‑11 Dickson Avenue  
1300 865 865  
+61 2 8436 8585  
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