Prototype Pollution Affecting litespeed.js package, versions <0.3.12

  • Exploit Maturity

    Proof of concept

  • Attack Complexity


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  • snyk-id


  • published

    16 Feb 2022

  • disclosed

    24 Jan 2022

  • credit

    Alessio Della Libera of Snyk Research Team

How to fix?

Upgrade litespeed.js to version 0.3.12 or higher.


litespeed.js is a Lite & fast micro javascript framework that is easy to learn.

Affected versions of this package are vulnerable to Prototype Pollution. When parsing the query string in the getJsonFromUrl function, the key that is set in the result object is not properly sanitized leading to a Prototype Pollution vulnerability.


  1. add the following query string ?__proto__[polluted]=yes

  2. open the browser developer console. The property polluted has value yes