WordPress NAB Transact WooCommerce 2.1.0 Payment Bypass

`Title: Payment bypass  
  
  
  
Product: WordPress NAB Transact WooCommerce Plugin  
  
  
  
Vendor Homepage: https://woocommerce.com/products/nab-transact-direct-post/  
  
  
  
Vulnerable Version: 2.1.0  
  
  
  
Fixed Version: 2.1.2  
  
  
  
CVE Number: CVE-2020-11497  
  
  
  
Author: Jack Misiura from The Missing Link   
  
  
  
Website: https://www.themissinglink.com.au  
  
  
  
Timeline:  
  
  
  
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:  
  
  
  
https://example-site.com/?wc-api=WC_Gateway_Nab_Direct_Post&order=XXXX&key= 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  
  
  
  
https://www.themissinglink.com.au/security-advisories  
  
  
  
  
  
  
  
  
Jack Misiura​  
  
  
Application Security Consultant  
  
  
  
  
a  
  
  
  
9‑11 Dickson Avenue  
  
  
Artarmon  
  
  
NSW  
  
  
2064  
  
  
  
p  
  
  
1300 865 865  
  
  
  
os  
  
  
+61 2 8436 8585  
  
  
  
w  
  
  
<https://www.themissinglink.com.au/> themissinglink.com.au  
  
  
  
  
  
  
  
  
  
  
  
  
<https://www.linkedin.com/company/the-missing-link-pty-ltd/>   
  
<https://www.facebook.com/The-Missing-Link-268395013346228/?ref=bookmarks>   
  
<https://twitter.com/TML_au>   
  
<https://www.youtube.com/channel/UC2kd4mDmBs3SjW4lX3fFHnQ>   
  
<https://www.instagram.com/the_missing_link_it/>   
  
  
  
  
  
  
  
<https://www.themissinglink.com.au/robotic-process-automation>   
  
  
  
  
  
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