Validation Bypass Affecting kind-of package, versions >=6.0.0 <6.0.3


0.0
low
  • Exploit Maturity

    Proof of concept

  • Attack Complexity

    High

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  • snyk-id

    SNYK-JS-KINDOF-537849

  • published

    19 Jan 2020

  • disclosed

    16 Dec 2019

  • credit

    Feng Xiao

How to fix?

Upgrade kind-of to version 6.0.3 or higher.

Overview

kind-of is a package that gets the native type of a value.

Affected versions of this package are vulnerable to Validation Bypass. It leverages the built-in constructor of unsafe user-input to detect type information. However, a crafted payload can overwrite this built in attribute to manipulate the type detection result.

PoC by Feng Xiao

var kindOf = require('kind-of');


var user_input = {
  user: 'barney',
  age: 36,
  active: true,
  "constructor":{"name":"Symbol"}
};
console.log(kindOf(user_input));

References